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A 
SYSTEM OF ANATOMY 



FOR THE USE OF 



STUDENTS OF MEDICIME. 



BY CASPAR WISTAR, M. D. 

LATE PROFESSOR OF ANATOMY IN THE UNIVERSITY OF 

PENNSYLVANIA. 



THIRD EDITION, 

WITH NOTES AND ADDITIONS. 



BY .WILLIAM EDMONDS HORNER, M. D. 

ADJUNCT PROFESSOR OP ANATOMX ITS THE UNIVERSITY OF PENNSIIiTAN?*. 
ME?IBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, &C. 



IN TWO VOLUMES. 

VOL. IL 



PHILADELPHIA : 
H. C. CAREY & I. LEA, 

1 823. 



Eastern District of Pennsylvania, to wit .• 

BE IT REMEMBERED, That on the tweiity-seventia day of October^ 
in the forty-eighth year of the Independence of the United States of 
America, A. D. 1823, James E. Moore, of the said district, hath deposited 
in this office the title of a book, the right whereof he claims as proprie- 
tor, in the words following, to wit : 

"A System of Anatomy for the use of the Students of Medicine. By 
" Caspar Wistar, M. D. Late Professor of Anatomy in the University 
" of Pennsylvania. Third Edition. With notes and additions. By 
"William Edmonds Horner, M. D. Adjunct Professor of Anatomy 
" in the University of fenusylvania, and member of the American Phi- 

; " losophical Society, &c. In two volumes. Volume II." 

In conformity to the act of the Congress of the United States, entituled, 
" An act for the encouragement of learning, by securing the copies of 
maps, charts, and books, to the authors and proprietors of such copies, 
during the times tlierein mentioned." And also to the act, entitled, 
" An act supplementary to an act, entitled, ' An act for the encourage- 
ment of learning, by securing the copies of maps, charts, and books, to 
the authors and proprietors of such copies during the times therein men- 
tioned,' and extending the benefits thereof to the arts of designing, en- 
graving, and etching historical and other prints." 

D. CALDWELL, Clerk of the Eastern 
District of Pennsylvania. 



CONTENTS OF VOL. II. 



i 



PART VI. 

OF THE NOSE—THE MOUTH— AND THE THROAT. 
CHAPTER L 

Of the Nose. 

SECTION I, 

Page 

Of the External Nose - - - - £ 

SECTION II. 
Of the Cavities of the Nose - - - - - 4 



CHAPTER II. 

Of the Mouth and the Salivary Glands. 

Of the Mouth ----- 14 

Of the Salivary Glands - - - - - 25 

CHAPTER III. 

Of the TJiroat. 

SECTION I. 

Of the Isthmus of the Fauces - . - " ^^ 

SECTION II. 

Of the Larynx .,_.--- 31 

Of the Thyroid Gland - - - . 37 

SECTION III. 

Of the Pharynx »------ 37 



iV CONTENTS. 

I PART VII. 

OF THE THORAX. 
CHAPTER I. 

Of the general Cavity of the Thorax, 

SECTION I. 

Of the Form of the Cavity of the Thorax ■=■ = 44 

SECTION II. 

Of the Arrangement of the Pleurge - - 45 

Preparation of the Thorax - - = - - 47 

CHAPTER II. 

Of the Heart and the Pericardium, and the Great Vessels con- 
nected with the Heart. 

SECTION I. 

Of the Pericardium - - - - 49 

SECTION II. 
Of the Heart ------- 50 

SECTION III. 

Of the Aorta, the Pulmonary Artery and Veins, and the 
Vense Cavse at their commencement - - 59 

CHAPTER IIL 

Of the Trachea and Lungs. 

SECTION I. 

Of the Trachea - - - - - - - 62 

The Black Glands on the Bronchise - - 64 

SECTION II. 

Of the Lungs - 65 

Thorax of the Foetus - - - -^ 69 

Physiological Observations, &c. - - 71 



CONTENTS. V 

PART Till. 

OF THE ABI OMEN. 

CHAPTER I. 

A general view of the Abdomen and Pelvis, and their Con- 
tents } with an Account of the Peritoneum. 

SECTION I. 

Construction of the Abdomen - - - 82 

Contents of the Abdomen ----- 85 

SECTION II. 

Of the Peritoneum - - - - 90 

CHAPTER II. 

Of the (Esophagus, the Stomach, and the Intestines. 

SECTION I. 
Of the CEsophagus . . _ - 94 

SECTION II. 
Of the Stomach 96 

Of the Gastric Liquor _ - . . loi 

SECTION III. 

Of the Intestines ._---- 104 

Division of the Intestines - - - 119 

The Small Intestines 110 

The Duodenum - - - - - 111 

Jejunum and Ileon 113 

The Mesentery - - - - - 115 

Of the great Intestines - - - - - 117 

The Csecum and Colon - - - 118 

The Rectum 122 

The Omentum - - - - 125 

CHAPTER III. • 

Of the Liver, the Pancreas, and the ^Zefim*** 

SECTION I. 
Of the Liver - 128 



Vi' CONTENTS . 

SECTION 11. 
Of the Pancreas . _ _ . 141 

SECTION III. 
Of the Spleen 145 

CHAPTER IV. 

Of the Urinary Organs, and the Glandulse Renales. 

SECTION I. 

Of the Glandulse Renales - - - 154 

SECTION II. 

Of the Kidneys and Ureters ~ - - - 155 

^ SECTION III. 

Of the Urinary Bladder - - - 162 

CHAPTER V. 

Of the Male Organs of Generation. 

SECTION I. 

Of the Testicles and their Appendages - - 171 

SECTION II. 

Of the Vesiculae Seminales and the prostate Gland 181 

SECTION III. 

Of the Penis .-.--_- 184 

CHAPTER VI. 

Of the Female Organs of Generation. 

SECTION I. 

Of the External Parts of Generation - - 200 

SECTION II. 

Of the Vagina ----- 203 

SECTION III. 

Of the Uterus, the Ovaries, and their Appendages 205 

SECTION IV. 

Of the bladder and Urethra ----- 213 



CONTENTS. Vn 

PART IX. 

OF THE BLOOD VESSELS. 

CHAPTER I. 

Of the Gmeral Structure and arrangement of the Blood Vessels. 

SECTION I. 
Of the Arteries . . . _ 226 

SECTION II. 
Of the Veins - - 233 

CHAPTER II. 

.& Particular Account of the Distribution of the Arteries. 

SECTION I. 

Of the Aorta, or the Great Trunk of the Arterial System 236 

' SECTION II. 

Of the Branches which go off from the Arch of the Aorta 238 

SECTION III. 

Of the. Branches which go off between the Arch and the 
Great Bifurcation of the Aorta - •■ 272 

SECTION IV. 

Of the Arteries which originate at and below the Great 
Bifurcation of the Aorta - - - - 283 

CHAPTER III. 

Of the particular Distribution of the Veins. 

SECTION I. 

Of the Superior, or Descending Vena Cava, and the Veins 
which communicate with it . _ . - 300 

SECTION II. 
Of the Inferior Vena Cava, and the veins connected 
with it ..._.- 309 



Viil CONTENTS. 

PART X. 

OF THE NERVES. 

Nerves of the Brain - - ^ - ^ ^ 523 

Of the Cervical Nerves . - - = 343 

Nerves of the Diaphragm - - - - - 346 

Brachial Plexus - - - - 347 

Nerves of the Arm ,_..-- 348 

The Dorsal Nerves - - - - 352 

Of the Lumbar Nerves - - - - - 353 

The Sacral Nerves - . . . 356 

Sciatic Plexus 357 

Great Sciatic Nerve - - - - 358 

Great Sympathetic Nerve 361 

Nerves of the Heart - - - ■ - 363 

Nerves of the Abdominal Viscera - - - - 368 

PART XI. 

OF THE ABSORBENT VESSELS. 

CHAPTER L 

Of the Jihsorhents of the Lower Extremities-^the Mdomen and 
the Thorax. 

SECTION I. 

The Absorbents of the Lower Extremities - 376 

SECTION II. 

The Absorbents of the Abdomen and Thorax - 381 

CHAPTER II. 

Of the Msorhenis of the Head and Neck, of the Upper Extre- 
mities, and the Upper Part of the Trunk of the Body. 

SECTION L 

Of the Absorbents of the Head and Neck - - 391 

SECTION II. 

Of the Absorbents of the Arm, and Upper Part of the 
Trunk ...... 393 



1^ ,1^ TSTTT?'?' 'rv*^>~T7'^^.7!.-'^ 

POMFSY NV» 
PART VI. 



OF THE NOSE : THE MOUTH : AND THE THROAT. 



CHAPTER I. 

OF THE NOSE. 



The prominent part of the face, to which the 
word nose is exclusively applied in ordinary lan- 
guage, is the anterior covering of two cavities which 
contain the organ of smelling. 

These cavities are formed principally by the up- 
per maxillary and palate bones ; and, therefore, to 
acquire a complete idea of them, it is necessary to 
study these bones, as well as the os ethmoides, the 
vomer, and the ossa spongiosa inferiora, which are 
likewise concerned in their formation. 

In addition to the description of these bones, in 
the account of the bones of the head, it will be- use- 
ful to study the description of the cavities of the 
nose which follows it. See vol. I, page 64. 

After thus acquiring a knowledge of the bony 
structure, the student will be prepared for a descrip" 
tion of the softer parts. 

Vol. U. 1 



2 The Extei'nal JVose. 

SECTION I. 

Of the External JVose. 

The superior part of the nose is formed by the 
ossa nasi, and the nasal processes of the upper 
maxillary bones, which have been already descriljed; 
(see vol. I, pages 42 — 16.) but the inferior part, 
which is composed principally of cartilages, is much 
more complex in its structure. 

The orifice, formed by the upper maxillary and 
nasal bones, is divided by a cartilaginous plate, 
which is the anterior and inferior part of the septum, 
or partition between the two cavities of the nose. The 
anterior edge of this plate projects beyond the orifice 
in the bones, and continues in the direction of the 
suture between the ossa nasi. This edge forms an 
angle with the lower edge of the same cartilage, 
which continues from it, in a horizontal 'direction, 
until it reaches the lower part of tlie orifice of the 
nose, at the junction of the palatine processes of the 
upper maxillary bones ; where a bony prominence is 
formed, to which it is firmly united. The upper 
part of the anterior edge of this cartilage, which is 
in contact with the ossa nasi, is flat, and is continued 
into two lateral portions that are extended from it, 
one on each side, and form a part of the nose : these 
lateral portions are sometimes spoken of as distinct 
cartilages ; but they are really continiiations of the 
middle portion or septum. 

Below the lower edge of these lateral portions are 
situated the cartilages which form the orifices of the 
nose, or th© nostrils. Of these, there is one of con- 
siderable size, and several small fragments, on each 
side of the septum. Each of the larger cartilages 
forms a portion of an oval ring, which is placed ob- 
liquely on the side of the septum : so that the extre- 



Of the JVose. 3 

mity of the oval points downward and forward, 
while the middle part of the oval is directed upwards 
and backwards. The sides of this cartilage are flat, 
and unequal in breadth. The narrowest side is in- 
ternal, and projects lower down than the cartilagi- 
nous septum ; so that it is applied to its fellow of 
the other nostril. The external side is broader, and 
continues backward and upward to a considerable 
distance. 

The upper and posterior part of this oval ring is 
deficient ; but the remainder of the nostril consists 
of several small pieces of cartilage, which are fixed 
in a ligamentous membrane that is connected by each 
of its extremities to the oval cartilage, and thus com- 
pletes the orifice. 

The anterior parts. of the oval cartilages form the 
point of the nose ; and the ligamentous portions, the 
ala5 or lateral parts of the nostrils. * 

• When the external integuments and muscles are 
removed from the lower portion of the nose, so that 
the internal membrane and these cartilages only re- 
main, the internal membrane will be found attached 
to the whole bony margin of each orifice, and to eacii 
side of the whole anterior edge of the middle carti- 
lage, which projects beyond the bones. This mem- 
brane is afterwards continued so as to line the oval 
cartilages and the elastic membrane of the ala nasi, 
to the margin of the orifice of the nostril. 

The internal portions of the oval cartilages being 
situated without the septum, and applied to each 
other, they form the external edge of the partition 
between the nostrils, or the columnanasi; which is 
very moveable upon the e.iX^'^ of the middle cartilage. 

The orifices of the nostrils, thus constructed, are 
dilated by that portion of the muscle, called Levator 
Labii Superioins Alaeque JVasi, which is inserted 
into the al:e nasi. 



4 Of the Cavities of the JVose. 

They are drawn down by the depressor labii su- 
perioris alseque nasi. They are pressed against the 
septum and the nose by the muscle called Compres- 
sor JVaris, which has however an opposite effect 
when its upper extremity is drawn upwards by those 
fibres of the occipito-fron talis, which descend upon 
the nose, and are in contact with it. 

The end of the nose is also occasionally drawn 
down, by some muscular fibres which descend from 
it, on the septum of the nose, to the orbicularis oris : 
they are considered as a portion of this muscle by 
many anatomists, but were described by Albinus as 
a separate muscle, and called JVasalis Labii Supe- 
rioris. 

When inspiration takes place with great force, the 
alae nasi would be pressed against the septum if they 
were not drawn out and dilated by some of the mus- 
cles above mentioned. 

SECTION 11. 

Of the Cavities of the JVose. 

To the description of the osseous parts of the na- 
sal cavities in vol. I, page 64, it ought now to be 
added that the vacuity in tbe anterior part of the os- 
seous septum is filled up by a cartilaginous plate, 
connected with the nasal lamella of the ethmoid bone 
above, and with the vomer below. This plate sends 
off those lateral portions already described, which 
form the cartilaginous part of the bridge of the nose. 

It should also be observed that at the back parts 
of these cavities are two orifices called the Posterior 
JVares, which are formed by the palate bones, the 
vomer, and the body of the sphenoidal bone, and are 
somewhat oval. 

The nasal cavities, thus constructed, are lined by 
a peculiar membrane, which is called pituitary from 



Schneiderian Memhrane. 5 

its secretioD of mucus, or Schneiderian after an ana- 
tomist who described it with accuracy.* 

This membrane is very thick and strong, and 
abounds with so many blood vessels, that in the liv- 
ing subject it is of a red colour. It adheres to the 
bones and septum of the nose like the periosteum, 
but separates from them more easily. The surface 
which adheres to the bones has some resemblance 
to periosteum ; while the other surface is soft, spon- 
gy, and rather villous. Bichat seems to have con- 
sidered this membrane as formed of two laminae, viz. 
periosteum, and the proper mucous membrane ; but 
he adds, that it is almost impossible to separate them. 

It has been supposed that many distinct glandu- 
lar bodies were to be seen in the structure of this 
membrane by examining the surface next to the 
bones :f but this opinion is adopted by very few of 
the anatomists of the present day. The texture of 
the merabiane appears to be uniform ; and on its sur- 
face are a great number of follicles of various sizes, 
from which flows the mucus of the nose. 

These follicles appear like pits, made by pushing 
a pin obliquely into a surface which retains the form 
of the impression. They can be seen very distincily 
with a common magnifying glass when the mem- 
brane is immersed in water, both on the septum and 
on tlie opposite surface. They are scattered over 
the membrane without order or regularity, except 
that in a few places they occur so as to form lines of 
various lengths, from half an inch to an inch. Tiie 
largest of them are in the lower parts of the cavities. 

It may be presumed that the secretion of mucus is 
effected here by vessels which are mere continuations 
of arteries spread upon a surface analogous to the 

• Conrad Schneider, a German professor, in a large work, " De 
Catarrhis," published aboui 1660. 
t See Wiuslow, section X. No. 337. 



6 Olfactory JVei^es. 

exhalents, and not convoluted in circumscribed mass- 
es, as in the case of ordinary glands. 

The arteries of this membrane are derived from 
various sources : the most important of them is the 
nasal branch of the internal maxillary, which passes 
into the nose throu2;h the spheno-palatine foramen, 
and is therefore called the Sj)]ieno-jmlatine Artery. 
It divides into several twigs, which are spent upon 
the dia'erent parts of the surface of the nasal cavities. 
Tvvo of them are generally found on the septum of 
the nose : one, which is small, passes forwards near 
the middle; the other, which is much larger, is near 
the lower part of it. 

Two small arteries called the anterior and jtoste- 
rior ethmoidal, which are branches of the ophthal- 
mic, enter the nose by foramina of the cribriform 
plate of the ethmoidal bone. These arteries pass 
from the orbit to the cavity of the cranium, and then 
through the cribriform plate to the nose. In addi- 
tion to these, there are some small arteries derived 
from the infra orbital, the alveolar and the palatine, 
wiiich extend to the Schneiderian membrane ; but 
they are not of much importance. 

The veins of the nose correspond with the arteries. 
Those which accompany the ethmoidal arteries open 
into the ocular vein of the orbit, which terminates 
in the cavernous sinuses of the head. The other 
veins ultimately terminate in the external jugulars. 

The nerves of the nose form an important part of 
the structure ; they are derived from several sources ; 
but the most important branches are those of the ol- 
factory. 

The olfactory nerves form oblong bulbs, which lie 
on each side of the crista galli, on the depressed por- 
tions of the cribriform plate of the ethmoid bone, 
within the dura mater. These bulbs are of a soft con- 
sistence, and resemble the cortical part of the brain 



3 



Olfactory A^'erves. 7 

mixed with streaks of medullary matter. They send 
off numerous filaments, which pass through the fora- 
mina of the ethmoid bone, aud receive a coat from 
the dura mater as they pass through it. 

These ^laments are so arranged that they form 
two rows, one running near to the septum, and the 
other to the surface of the cellular part of the eth- 
moid bone, and the os turbinatum: and in addition 
to these are some intermediate filaments. 

When the Schneiderian membrane is peeled from 
the bones to which it is attached, these nervous fila- 
ments are seen passing from the foramina of the eth- 
moid bone to the attached surfaces : one row passin 
upon that which covered the septum, and the other 
to that of the opposite side ; while the intermediate 
filaments take an anterior direction, but unite to the 
membrane as soon as they come in contact with it. 

All of these can be traced downwards on the 
aforesaid surfaces of the membrane for a consider- 
able distance, when they gradually sink into the 
substance of the membrane, and most probably ter- 
minate on the internal villous surface ; but they have 
not been traced to their ultimate termination. They 
ramify so tliat the branches form very acute angles 
with each other. On the septum the different branches 
are arranged so as to form brushes, which lie in con- 
tact with each other. On the opposite sides, the dif- 
ferent ramifications unite so as to form a plexus. 

JDr. Soemmering published last year some very 
elegant engravings of the nose, representing one of 
his dissections, which appears to have been uncom- 
monly minute and successful.* These represent 
the ramifications as becoming more expanded and 
delicate in the progress towards tlieir terminations, 

* They are entitled, Icones organorum humanonim olfactus. 



8 Spheno-palatine and other JVerves of the JVose. 

and as observing a torturous course, with very short 
meandering flexures. 

It is to be observed that the ramifications of the 
olfactory nerve, thus arranged, do not extend to the 
bottom of the cavity. On the external side, they 
are not traced lower than the lower edge of the eth- 
moid, or of the superior spongy bone : and on the 
septum, they do not extend to the bottom, although 
they are lower than on the opposite side. On the 
parts of the membrane not occupied by the branches 
of the olfactory nerves, several other nerves can be 
traced. The nasal twig of the ophthalmic branch 
of the fifth pair, after passing from the orbit into the 
cavity of the cranium, proceeds to the nasal cavity 
on each side by a foramen of the cribriform plate ; 
and after sending off some fibrillse, descends upon 
the anterior part of the septum to the point of the 
nose. The spheno-palatine nerve, which is derived 
from the second branch of the fifth pair, and enters 
the nose by the spheno-palatine foramen, is spread 
upon the lower part of the septum and of the opposite 
side of the nose also, and transmits a branch through 
a canal in the foramen incisivum to the mouth. Se- 
veral small branches also pass to the nose from the 
palatine and other nerves ; but those already men- 
tioned are the most important. 

A question has been proposed, whether the olfac- 
tory nerve is exclusively concerned in the function 
of smelling, or whether the other nerves above men- 
tioned are also concerned in it. It seems probable 
that this function is exclusively performed by the 
olfactory nerve, and that the other nerves are like 
the opththalmic branch of the fifth pair, with respect 
to the optic nerve. In proof of this, it is asserted 
that the sense of smelling has entirely ceased in some 
cases, where the sensibility to mechanical irritation 
of every kind has remained unchanged. If the ol- 



Extent of the Schneiderian Membrane. 9 

factory nerve alone is concerned in the function of 
smelling, it follows, that tliis function must be con- 
fined to the upper pains of the nasal cavities ; but it 
ouD-bt to be remembered, that th.e structure of the 
Schneiderian membrane, in the lower parts of these 
cavities, appears exactly like that which is above. 
. The surface of the nasal cavities and their sep- 
tum, when covered with the Schneiderian membrane, 
corresponds with the osseous surface formerly des- 
cribed. The membrane covers the bones and car- 
tilage of the septum, so as to make one uniForm re- 
gular surface. From the upper part of the septum, 
it is continued to the under side of the cribriform 
plate of the ethmoid, and lines it; the filaments of 
the olfactory nerve passing through the foramina of 
that bone into the fibrous surface of the membrane. 
It is continued from the septum, and from the cribri- 
form plate, to the internal surface of the external 
nose, and lines it. It is also continued backwards 
to the anterior surface of the .body of the sphenoidal 
bone ; and, passing through the foramina or openings 
of the sphenoidal cells, it lines these cavities com- 
pletely ; but in these, as well as the other cavities, 
its structure appears somewhat changed : it becomes 
thinner and less vascular. 

At the above mentioned foramina, in some sub- 
jects, it forms a plait or fold, which diminishes the 
aperture considerably. 

From the upper surface of the nasal cavities, the 
membrane is continued downwards over the surface 
opposite to the septum. On the upper flat surfaces 
of the cellular portions of the ethmoid, it forms a 
smoothuniform surface. After passing over the first 
turbinated bone, or that called after Morgagni, it ia 
reflected into the groove, or upper meatus, immedi- 
ately within and under it : the fold formed by tha 
membrane, as it is reflected into the meatus, is rather 

Vol. II. 3 



lO Distribution of the Schneiderian Membrane* 

larger than the bone ; and the edge of the fold there- 
fore extends lower down than the edge of the bone, 
and partly covers the meatus like a fiap, consisting' 
only of the doubled membrane. This fold generally 
continues backwards as far as the spheno-raaxillary 
foramen, which it closes ; the periosteum, exterior to 
the foramen, passing through it, and blending itself 
with the fibrous surface of the Schneiderian mem- 
brane within. Here the spheno-palatiue nerves and 
arteries join the membrane. Below this meatus, it 
extends over the middle (formerly called the upper) 
turbinated bone, and is reflected or folded inwards 
on the under side of this bone, and continued into 
the middle meatus below it. In the middle meatus, 
which is partly covered by the last mentioned turbi- 
nated bone, there are two foramina : one communi- 
cating with the maxillary sinus ; and the other with 
the anterior cells of the ethmoid and the frontal si- 
nuses. The aperture into the maxillary sinuses is 
much less in the recent head, in which the Schnei- 
derian membrane lines the nose, than it is in the 
bare bones. A portion of the aperture in the bones 
is closed by the Schneiderian membrane, which is 
extended over it : the remainder of the aperture is 
unclosed ; and through this foramen, the membrane 
is reflected so as to line the whole cavity. As a por- 
tion of the foramen is covered by the membrane, and 
this portion as well as the other parts of the cavity 
is lined by the membrane, it is obvious that at the 
place where the membrane is extended over the 
foramen in the bone, it must be doubled ; or, in 
other words, a part of the aperture of the maxillary 
sinus is closed by a fold of the Schneiderian mem- 
brane. 

This aperture varies in size in different subjects, 
and is often equal in diameter to a common quill. It is 
situated in the middle of the meatus, and is covered 



Eustachian Tube, 11 

by the middle turbinated bone : immediately above \iy 
is a prominence of the cellular structure of the eth- 
moid bone, which has a curved or semicircular 
fi2;ure. Near this prominence, in the same meatus, 
a groove terminates, which leads from the anterior 
ethmoid cells and the frontal sinuses. 

From the middle meatus, the meinbrane proceeds 
over the inferior turbinated bone, and is reflected 
round and under it into the lower meatus. It appears 
rather larger than the bone which it covers; and 
therefore the lower edge of the bone does not extend 
so low as the lower eds:e of the membrane, which of 
cour>»e is like a fold or plait. The membrane then 
continues and lines the lower meatus : here it ap- 
pears less full than it is in the turbinated bone, tn 
this meatus, near to its anterior end, is the lower ori- 
fice of the lachrymal duct : this is simply lined by 
the Schneiderian membrane, which is continued into 
it, and forms no plaits or folds that affect the orifice. 

Orifice of the Eustachian Tube. 

Immediatety behind each of the nasal cavities, on 
the external side, is the orifice of the Eustachian 
Tube. It has an oval form, and is large enough to 
admit a very large quill. Its position is oblique; 
the upper extremity being anterior to the other parts 
of the aperture, and on a line with the middle mea- 
tus, while the centre is behind the inferior turbinated 
bone. The lower part of the oval is deficient. This 
tube is formed posteriorly by a cartilaginous plate. 
It is lined by the membrane continued from the nose. 

The cavities of the nose answer a twofold purpose in the 
animal economy : they afford a surface for the ex- 
pansion of the olfactory nerves ; and a passage for 
the external air to the windpipe, in respiration. 

The function of smelling appears to be dependent, to 
a certain degree, upon respiration. It has been a?- 



12 Observations respecting the JVose. 

serted that unless the air passes in a stream through 
the nose, as in respiration, the perception of odour 
does not take place ; that in persons who breathe 
through wounds and apertures in the windpipe, the 
function of smelling is not performed. It is rather 
in confirmation of this proposition, that most per- 
sons, when they wish to have an accurate perception 
of any odour, draw in air rapidly through the nose. 

Although the ultimate terminations of the olfactory 
nerves cannot be demonstrated like those of the optic 
and auditory nerves, it is probable, from the appear- 
ance of the fibres, while they are distinguishable, 
that they are finally arranged with great delicacy. 
. It is certain that the impressions from whence we 
derive the perceptions of many odours must be very 
slight ; as some odorous bodies w^ill impregnate the 
air of a large chamber, for a great length of time, 
without losing any sensible weight. 

With respect to delicacy of structure and sensibility, 
* it is probable that the nose holds a middle rank be- 

tween the eye or ear, and the tongue : and on this 
account the mucus is necessary as a covering and 
defence of its surface. 

it has been ascertained, by the investigations of che- 
mists, that this mucus contains the same ingredients 
as the tears already described, viz. animal mucus 
and water ; with muriate of soda, and soda uncom- 
bined; phosphate of lime, and phosphate of soda. 

The animal mucus, which is a most important ingre- 

\ dient in the composition, resembles the mucilage 
formed by some of the vegetable ,, gums in several 
particulars ; and differs from them in others. 

The mucus of the nose, if it remain there long after it 
is secreted, becomes much more viscid in consist" 
ence, and changes from a whitish colour to one 
which partakes more or less of the yellow. It is 
probable that an incipient putrefaction may occasion 
these changes in it. 

The use of the frontal, maxillary and other sinuses, 
communicating with the nose, has been the subject 
of some inquiry. As there can be no stream of air 
through them, and as the membrane lining them is 



Use of the Sinuses of the JSTose. 13 

neither so thick, villous nor flexible as that lining 
the nose, it may be concluded, a priori, that they 
are not concerned in the function of smelling. This 
opinion is strengthened by the fact, that very young 
children, in whom these sinuses scarcely exist, en- 
joy the sense of smelling in perfection. The follow- 
ing fact is also in support of it. The celebrated 
Dessault attended st patient, in whom one of the 
frontal sinuses was laid open by the destruction of 
the bone which covered it anteriorly. This patient 
was able to breathe a short time through the sinus 
when the mouth and nose were closed : At the re- 
quest of Dessault he breathed in this manner when 
a cup of some aromatic liquor was held near the 
opening of the sinus : and had not the least percep- 
tion of odour. This experiment was repeated seve- 
ral times. 
Many physiologists believe that these sinuses have an 
effect in modulating the voice. ^ 



CHAPTER II. 

OF THE MOUTH. 

The general cavity of the mouth is formed ante- 
riorly and laterally by the connexion of the lips and 
checks to the upper and lower jaws ; so that the 
teeth and the alveoli of both jaws may be considered 
as within the cavity. Above, it is bounded j>rinci- 
pally by the palatine processes of the upper maxil- 
lary and palate bones, and the soft palate, which con- 
tinues backward from them in the same direction. 

Below, the cavity is completed by several mus- 
cles, which proceed from almost the whole internal 
circumference of the lower jaw, and, by their con- 
nexions with each other, with the tongue and the os 
hyoides, form a floor or bottom to it. The tongue is 
particularly connected to this surface, and may be 
considered as resting upon and supported by it. 

To acquire an idea of the parietes of this cavity, 
after studying the upper and lower maxillary bones, 
the orbicularis oris and the muscles connected with 
it, especially the buccinator, ought to be examined ; 
and also the digastricus, the mylo-hyoideus, genio- 
hyoideus, and genio-hyoglossus. By this it will 
appear that the lips and cheeks, and the basis or 
floor of the mouth, are formed in a great measure by 
muscles. Upon the internal surface of these mus- 
cles, a portion of cellular and adipose substance is 
arranged, as well as glandular bodies of different 
sizes ; and to these is attached the membrane which 
lines the inside of the mouth. 

This membrane passes from the skin of the face 
to the lips, and the inside of the mouth ; and, al- 
though it is really a continuation of the skin, there 



Internal Surface of the Mouth. 15 

is so great a change of structure, that it ought to Le 
considered as a diff'erent membrane. At the orifice 
of the lips it is extremely thin, and so vascular that 
it produces the fine florid colour which appears there 
in health. It is covered by a cuticle, called by some 
anatomists. Epithelium, which has a proportionate 
degree of delicacy, and can be separated like the cu- 
ticle in other parts. ♦When this cuticle is separated, 
the lips and the membrane of the mouth, appear to 
be covered with very fine villi, which are particular- 
ly apparent in some preparations of the lips after in- 
jection and maceration.* 

Under this membrane are many small glandular 
bodies of a roundish form, called glandulse labiales, 
whose excretory ducts pass througk it to the inner 
surface of the mouth, for the purpose of lubrifying 
it with their secretion, which is mingled with the 
saliva. ^ 

The membrane, which lines the inside of the lips 
and cheeks, is somewhat different from that which 
forms the surface of the orifice of the mouth : it is not 
so florid ; the blood vessels in its texture are larger 
and not so numerous. This change, however, takes 
place very gradually, in the progress of the mem- 
brane, from the orifice of the lips to the back part of 
the cheeks. Glandular bodies, like those of the lips, 
are situated immediately exterior to this membrane 
of the cheeks, between it and the muscles : their 
ducts open on its surface. These glands are called 
Buccales. 

This lining membrane is continued from the inter- 
nal surface of the lips and cheeks to the alveolar 
portions of the upper and lower jaws, which are in 
the cavity of the mouth, and covers them, adhering 
firmly to the periosteum. 

♦ Ruysch had a fine preparation of this stnicture. See\Thesaurus 
VII. Tab. III. Fig. 5. \ 



16 Gums. — Surface of the Hard Palate, 

.The teeth appear to have passed through aper- 
tures in this membrane, and are surrounded by it 
closely at their respective necks. 

The portion of membrane, which thus invests the 
jaws, constitutes the gums; which have now acquir- 
ed a texture very different from that of the mem- 
brane, from which they were continued. They are 
extremely firm and dense, and^very" vascular. It is 
probable that their ultimate structure is not perfectly 
understood. 

In the disease called scurvy, they tumify and lose 
the firmness of their texture : they acquire a livid co- 
lour, and are much disposed to hemorrhage. 

From the alveoli of the upper jaw, the lining mem- 
brane is continued upon the palatine processes of the 
upper maxillary and palate bones, or the roof of the 
mouth. 

This membrane of the palate is not quite so firm 
as that of the gums, and is also less fioria : it ad- 
heres firmly to the periosteum, and thus is closely 
fixed to the bones. There is generally a ridge on 
its surface, immediately under the suture between 
the two upper maxillary bones ; and some transverse 
ridges are also to be seen upon it. On the internal 
surface of this membrane are small glandular bodies, 
whose ducts open on the surface of the palate. 

It is asserted, that this membrane has a limited 
degree of that sensibility which is essential to the 
function of tasting ; and, that if certain sapid sub- 
stances are carefully applied to it, their respective 
tastes will be perceived, although they have not been 
in contact with the tongue. 

The miembrane is continued from the bones above 
mentioned to the soft palate, or velum pendulum pa- 
lati, which is situated immediately behind them. This 
soft palate may be considered as a continuation of 
the partition between the nose and mouth : it is at- 



Soft Palate. — Uvula, 17 

taclied to the posterior ed^e of the palatine processes 
of the ossa palati, and to the pterygoid processes of 
the sphenoidal bone. Its interior structure is mus- 
cular. The upper surface is covered by the mem- 
brane of the nose, the lower surface by the membrane 
which lines the mouth. 

The muscles; which contribute to the composition 
of this structure, are the circumilexi and the le- 
vatores palati above, and the constrictores isthmi 
faucium and palatopharyngei below. (See vol. I. 
page 190 — 191.) Thus composed, the soft palate 
constitutes the back part of the partition between 
the nose and mouth. When viewed from before, 
with the mouth open, it presents towards the tongue 
an arched surface, which continues downwards on 
each side until it comes nearly in contact with the 
edges of that organ. On each of the lateral parts of 
this arch, are two pillars, or rather prominent ridges, 
which project into the month. These ridges are at 
some distance from each other below, and approach 
much nearer above, so that they include a triangular 
space. They are called the lateral half arches of 
the palate. Each of them is formed by a plait or 
fold of the lining membrane of the mouth, and contains 
one of the two last mentioned muscles : the anterior, 
the constrictor isthmi faucium ; the posterior, the pa- 
lato-pharyngeus. These muscles, of course, draw the 
palate down toward the tongue when tliey contract. 

From the centre of the arch, near its posterior 
edge, is suspended the uvula, a conical body, which 
varies in length from less than half an inch to rather 
more than one inch. It is connected by its basis to 
the palate ; but its apex is loose and pendulous. 
This body is covered by the lining membrane of the 
mouth. It contains many small glands, and a mus- 
cle also, the azygos uvulae, which arises fram the 
posterior edge of the ossa palati, at the suture which 

Vol. it. 3 



18 The Tongue. 

connects them to each other, and, passing posteriorly 
upon the soft palate, extends from the basis to the 
apex of the uvula, into which it is inserted. By the 
action of this muscle, the length of the uvula can be 
very much diminished ; and when its contraction 
ceases, tiiat body is elongated. 

The pendulous part of the uvula can also be 
moved, in certain cases, to either side. 

It is commonly supposed, that the principal use of 
this little organ is to modulate the voice ; but there 
are good reasons for believing, that it has another 
object. It was remarked by Fallopius, (and the ob- 
servation has been confirmed by many surgeons since 
his time) that the uvula may be removed completely 
without occasioning any alteration of the voice, or 
any difficulty in deglutition, if the soft palate be left 
entire. 

The soft palate is so flexible, that it yields to the 
actions of the levatores palati, which draw it up so 
as to close the posterior nares completely. 

It also yields to the circumflexi or tensores, which 
stretch it so as to do away its arched appearance. 

It is therefore very properly called the Palatmn 
Molle. It is also frequently called the Velum Pen- 
dulum palati ^ from the position which it assume*. 

The Tongue, 

Which is a very important part of this structure, 
is retained in its position and connected with the parts 
adjoining it, by the following arrangements. 

The OS hyoides, which, as its name imports, re- 
sembles the Greek letter v, or half an oval, is situat- 
ed rather below the angles of the lower jaw, in the 
middle of the upper part of the neck. It is retained 
in its position by the sterno-hyoidei muscles, which 
connect it to the upper part of the sternum ; by the 
coraco-hyoidei, which pass to it obliquely from the 



Structure of the Thngue. 19 

scapula; by the thyro-byoidei, wbich pass to it di- 
rectly upward from the thyroid cartilage : all of 
wbich connect it to parts below. To these should 
be added the stylo-byoidei, which pass to it oblique- 
from behind and rather from above; the mylo- 
hyoidei, which come rather anteriorly from the late- 
ral parts of the lower jaw ; and the genio-hyoidei, 
which arise from a situation directly anterior and 
superior, the chin. When tliese muscles are at rest, 
the situation of the os hyoides is, as above described, 
below the angles of the lower jaw: when those, in 
one particular direction, act while the others are 
passive, the bone may be moved upwards or down- 
wards, backwards or forwards, or to either side. 
This bone may be considered as the basis of the 
tongue ; for the posterior extremity of that organ is 
attached to it ; and of course the movements of the 
bone must have an immediate effect upon those of 
the tongue. 

The tongue is a flat body of an oval figure, but 
subject to considerable changes of form. 

The posterior extremity, connected to the os hy- 
oides, is commonly called its basis ; the anterior ex- 
tremity, which when the tongue is quiescent, is 
rather more acute, is called its apex. 

The lower surface of the tongue is connected with 
a number of muscles, which are continued into its 
substance. This connexion is such, that the edges 
of the tongue are perfectly free and unconnected ; 
and so is the anterior extremity for a considerable 
distance from the apex towards tJie base. 

The substance of the tongue consists principally 
of muscular fibres intermixed with a delicate adipose 
substance. It is connected to the os hyoides by the 
hyoglossus muscle and also by some other muscular 
ftbres, as well as by a dense memhranous substance, 
which appears to perform the part of a ligament. 



20 . Structure of the Tongue. 

This connexion is also strengthened by the continu- 
ance of the integuments from the tongue to the epi- 
glottis cartilage, to be hereafter described ; for that 
cartilage is attached by ligaments to the os hyoides. 

The tongue is thin at its commencement at the os 
Iiyoides ; but it soon increases in thickness. The 
muscular fibres in its composition have been consi- 
dered as intrinsic, or belonging wholly to its internal 
structure; and extrinsic, or existing in part outside 
of this structure. The linguales muscles are intrin- 
sic : (Vol. I, page 189,) they are situated near the 
under surface of the tongue, one on each side, sepa- 
rated from each other by the genio-hyo-glossi mus- 
cles, and extending from the basis of the tongue to 
its apex. These muscles can be easily traced as above 
described ; but there are also many fibres in the 
structure of the tongue, Avhich seem to pass in every 
direction, and of course are difi*erent from tliose of 
the linguales muscles. To these two sets of fibres 
are owing many of the immensely varied motions of 
the different parts of the tongue. 

In addition to these, are the extrinsic muscles, 
which originate from the neighbouring parts, and 
are inserted and continued into the substance of the 

tOHgUC. 

Among the most important of these muscles, are 
those which proceed from the chin, or the genio- 
hyo-glossi. They are in contact with each other; 
their fibres radiate from a central point on the inside 
of the chin, and are inserted into the middle of the 
lower surface of the tongue : the insertion commenc- 
ing at a short distance from its apex, and continuing 
to its base. 

As the genio-hyo-glossi muscles have a consider- 
able degree of thickness, they add much to the bulk 
of the tongue in the middle of the posterior parts of it. 

The hyo-glossi and the stylo-glossi, being conti- 



Papillse of the Tongue. 21 

uued into the posterior and lateral parts^ contribute 
also to the bulk of these parts. 

The tongue, thus composed and connected, lies, 
when at rest, on the mylo-hyoidei muscles ; and the 
space between it and thesemuscles is divided into two 
lateral parts by the above described genio-hyo-glossi. 
In the space above mentioned, is a small salivary 
gland, of an irregular oval form ; the greatest diameter 
of which extends from before backwards, and its 
edges present outwards and inwards. It has several 
excretory ducts, the orifices of whicli form a line on 
each side of the tongue. This gland is very promi- 
nent under the tongue ; and when the tongue is rais- 
ed it is particularly conspicuous : it is called the 
SuhlinguaL 
. The lining membrane of the mouth continues from 
the inside of the alyeoli of the lower jaw, which it 
covers, over the sublingual glands to the lower sur- 
face of the tongue. In this situation it is remarkably 
tiiin : but, as it proceeds to the upper surface of the 
tongue, its texture changes considerably ; and on 
this surface it constitutes the organ of taste. 

The upper surface of tlie tongue, although it is 
continued from the thin membrane above described, 
is formed by a rough integument which consists, like 
the skin, of three laminae. The cuticle is very thin ; 
and under it, tiie rete raucosum* is thicker and 
softer tlian in other places. 

The true skin here abounds with eminences of 
various sizes and forms, all of which are denominat- 
ed Papillse. The largest of these are situated on 
the posterior part of the tongue, and are so arranged 
that they form an angle rather acute, with its point 

* M. Bichat appears to have had doubts whether the real rete 
mucosum existed here. He says that he could only perceive a 
decussalion of vessels in the intervals of the papilla:, which, as he 
supposes, occasioned the florid colour of the tongue. 



SS Papillx of the Tongue. 

backwards. Thty are commonly nine in number : 
they resemble an inverted cone ; or, are larger at 
their head than their basis. They are situated in 
pits or depressions, to the bottoms of which they are 
connected. In many of them there are follicles, or 
perforations, whicli have occasioned them to be re- 
garded as glands. They are called Papillae Maxi- 
msSf or Capitatce. 

The papillae, next in size, are denominated/wTz^z- 
foi'm by some anatomists, and Medise or Semilenti- 
culares by others. They are nearly cylindrical in 
form, with their upper extremities regularly rounded. 
They are scattered over the upper surface of tJie 
tongue, in almost every part of it, at irregular dis- 
tances from each other. 

The third class are called conoidal or villous. 
They are very numerous, and occuj)y the greatest 
part of the surface of the tongue. Although they arc 
called conoidal, there is a great difterence in their 
form ; many of them being irregularly angular and 
serrated, as well as conical. 

Soemmering and other German anatomists consi- 
der the smallest papillae as a fourth class, which 
they call i\\^ filiform : these lie between the others. 

It is probable that these papillae are essential 
parts of the organ of taste; and their structure is of 
course an interesting object of inquiry. 

The nerves of the tongue have been traced to the 
papillae, and have been compared by some anato- 
mists to the stalk of the apple, while the papillae 
resembled the fruit ; but their ultimate termination 
does not appear to have been ascertained. *- 

* In the explanation of the plates, referred to in the following 
sentence, Soemmering observes, that when the fibrillx of the lin- 
gual nerve of the fifth pair are traced to the papillae 'if the second 
class, they swell out mto a conical form ; and these nervous cones 
are in such close contact with each other, that the point of the 
finest needle could not be insinuated into the papillx without 
touching a nerve. 



Blood vessels of the Tongue. 28 

Soemraering has lately published some eleganfc 
engraved copies of drawings of these papillae, when 
they were magnified twenty-five times ; from which 
it appears that a very large number of vessels, par- 
ticularly of arteries, exist in them. These vessels 
are arranged in a serpentine direction, and are pro- 
minent on the surface; but they appear doubled, 
and the most prominent part is the doubled end. — 
This arrangement of vessels is perceptible on the 
sides of the tongue, as well as on the papillae. 

Behind the large papillae is a foramen, first de- 
scribed by Morgagni, and called by him Foramen 
Csecuin. It is the orifice of a cavity which is not 
deep ; the excretory ducts of several mucous glands 
open into it. 

On the upper surface of the tongue, a groove is 
often to be seen, which is called the linea mediana, 
and divides it into two equal lateral parts. Below, 
the lining membrane of the mouth, as it is continued 
from the lower jaw to the tongue, forms a plait, 
which acts as a ligament, and is called ih&frsenum 
Unguse. It is attached to the middle of the tongue, 
at some distance behind the apex. 

The tongue is well supplied with blood vessels, 
which are derived from the Ungual branch of the 
external carotid on each side. This artery passes 
from the external carotid, upwards, inwards, and 
forwards, to the body of the tongue. In this course 
it sends off several small arteries to the contiguous 
parts, and one, which is spent about the epiglottis 
and the adjoining parts, called the Dorsalis Linguw. 
About the anterior edge of tiie hyo-glossus muscle, 
it divides into two large branches : one of which, 
called the Sublingual^ passes under the tongue be • 
twcen the genio-hyo-glossus and thesublingualgland, 
and extends near to the symphysis of the upper jaw; 
sending branches to the sublingual gland, to the 



24 Blood vessels of the Tongue. 

muscles under the tongue, to the skin, and the lower 
lip. The other is in the substance of the tongue, 
on the under side near the surface, and extends to 
the apex. 

The veins of this organ are not so regular as the 
arteries: they communicate with the external jugu- 
lar ; and some of them are always very conspicuous 
under the tongue : these are called raniilar. 

It is to be observed, that the vessels on each side 
have but little connexion with each other ; for those 
of one side may be injected while the others continue 
empty. 

The tongue is also well supplied with nerves, 
and derives them from three diiferent sources on 
each side, viz, from the fifth, the eighth, and ninth 
pairs of the head. 

The lingual portion of the third branch of the fifth 
pair, passing under the tongue, enters its substance 
about the middle, and forms many minute branches, 
which pass to the papillse of the fore part of the 
tongue. 

'Fhe glosso-pharyngeal portion of the eighth pair, 
sending oif several branches in its course, passes to 
the tongue near its basis, and divides into many 
small branches, which are spent upon the sides and 
middle of the root of the tongue, and also upon the 
large papillae. 

The ninth pair of nerves are principally appro- 
priated to the tongue. They pass on each side to 
the most fleshy part of it, and after sending one 
branch to the raylo-hyoideus, and another to com- 
municate with the lingual branch of the fifth pair, 
they are spent principally upon the genio-glossi, 
and linguales muscles. 

The tongue answers a threefold purpose. It is 
the principal organ of taste. It is a very important 
agent in the articulation of words ; and it assists in 



Salivary Glands. 25 

those operations upon our food, which are perform- 
ed in the mouth. 

The Salivary Glands. , 

The salivary glands have such an intimate con- 
nexion with the mouth that they may be described 
with it.* 

There are three principal glands on each side: 
the Parotid* the Submaxillary and the Sublingual. 
They are of a whitish or pale flesh-colour, and are 
composed of many small united masses or lobuli, 
each of which sends a small excretory duct to join 
similar ducts from the other lobuli, and thereby form 
the great duct of the gland. 

The Parotid is much larger than the other glands. 
It occupies a large portion of the vacuity between the 
mastoid process and the posterior parts of the lower 
jaw. It extends from the ear and the mastoid pro- 
cess over a portion of the masseter muscle, and from 
the zygoma to the basis of the lower jaw. Its name 
is supposed to be derived from two Greek words 
which signify contiguity to the ear. It is of a firm 
consistence. It receives branches from the external 
carotid artery and from its facial branch. 

From the anterior edge of this gland, rather above 
the middle, the great duct proceeds anteriorly across 
the masseter muscle ; and, after it has passed over 
it, bends inward through the adipose matter of the 
cheek to the buccinator muscle, which it perforates 
obliquely and opens on the inside of the cheek op- 
posite to the interval between the second and third 
molar teeth of the uj)per jaw. The aperture of the 
duct is ratlier less than the general diameter of it, 
and this circumstance has the efl'ect of a valve. 
When the duct leaves the parotid, several small 
glandular bodies called socioe parotidis, are often 

* For a general account of glands, seethe appendix to this vohimp. 

Vol. J J. 4 



26 Parotid dnd Submaxillary Gtands. 

attached to it, and their ducts communicate with it. 
The main duct is sometimes called after Steuo, who 
first descrihed it. 

When the mouth is opened wide, as in gaping, 
there is often a jet of saliva from it into the mouth. 

The parotid gland furnishes the largest proportion 
of saliva. 

It covers the nerve called Portio Dura, after it 
has emerged from the foramen stylo-mastoideum. 

The second gland is called the Submaxillary. It is 
much smaller than the parotid, and rather round in 
form. It is situated immediately within the angle 
of the lower jaw, between it, on the outside, and the 
tendon of the digastric muscle and the ninth pair of 
nerves internally. Its posterior extremity is con- 
nected by cellular membrane to the parotid gland ; 
its anterior portion lies over a part of the raylo- 
hyoideus muscle ; and from it proceeds the excretory 
duct, which is of considerable length, and passes 
between the mylo-hyoideus and the genio-glossus 
muscles along the under and inner edge of the sub- 
lingual gland. In this course the duct is sometimes 
surrounded with small glandular bodies, which seem 
to be appendices of the sublingual gland. It termi- 
nates under the tongue, on the side of the frsenum 
linguae, by a small orifice which sometimes forms a 
papilla.* 

The orifice is often smaller than the duct ; in con- 
sequence of which, obstruction frequently occurs 
here, and produces the disease called ranula. 

The sublingual gland, which has already been 
mentioned, lies so that, when the tongue is turned 

♦ Lassus informs us that Oribases, afterwards all the Arabians, 
and subsequently Guy De Chauliac, Lanfranc, Achillini Berenger 
De Carpi, Charles Etienne, Casserius and several others have given 
the description of these salivary ducts, notAvithstanding which Whar- 
ton, a physician of London, attributed to himself the discovery of 
them on the bullock in 165e.~ED. 



Sublingual Gland. — Saliva. 27 

up, it can be seen protruding into the cavity of the 
mouth, and covered by the lining niembrnne, which 
seems to keep it fixed in its place. It lies upon the 
mylo-hyoideus, by the side of the genio-hyoideus ; 
and is rather oval in form and flat. Its greatest 
length is from before backwards; its position is ra- 
ther oblique, one edge being placed obliquely in- 
wards and upwards, and the other outwards and 
downwards. It has many short excretory tlucts, 
which open by orifices arranged in a line on each 
side : they are discovered with difficulty, on account 
of their small size, and sometimes amount to eighteen 
or twenty in numher. In some few instances, this 
gland sends off a single duct, which communicates 
with the duct of the submaxillary gland. 

The salivary fluid secreted by these glands is in- 
odorous, insipid, and limpid, like water; but much 
more viscid, and of greater specific gravity. Water 
constitutes at least four fiftlis of its bulk ; and animal 
mucus one half of its solid contents. It also con- 
tains some albumen, and several saline substances : 
as the muriate of soda, and the phosphates of lime, 
of soda, and of ammonia. 

It is probable that this fluid possesses a solvent 
power with respect to the articles of food. 

There are small glandular bodies, situated be- 
tween the masseter and buccinator muscles, opposite 
to the last molar tooth of the upper jaw, whose na- 
ture is not well understood : they are called Glan- 
dulse Molares. 

The motions of the tongue are very intelligible to a 
person who has a preparation of the lower jaw be- 
fore him, with the tongue in its natural situation, and 
the muscles, which influence it, properly dissected. 
Its complicated movements will appear the neces- 
sary result of the action of those muscles upon it, 
and the os hyoides ; and also upon the larynx, with 






28 Observations on the Tongue. 

which the os hyoides is connected. The muscular 
iibi'es of the tongue itself are also to be taken into 
this view, as they act a very important part. 

Although the tongue appears very necessary, in a me- 
chanical point of view, to the articulation of many 
words, yet there are cases where it has bisen en- 
tirely deficient, in which the parties, thus affected, 
have been able to speak very well in general, as 
well as to distinguish different tastes.* 

The tongue is also a very delicate organ of touch. We 
can perceive the form of the teeth, and the state of 
the surface of the mouth, more accurately by the 
application of the tongue than of the fingers. 

On the three nerves which go to the tongue, it is ge- 
nerally supposed that the lingual portion of the third 
branch of trie fifth pair is most immediately con- 
cerned in the function of tasting, as it passes to the 
front part of the surface of the tongue. The 
glosso-pharyngeal are probably concerned in the 
same function on the posterior part, while the ninth 
pair of nerves seems principally spent upon the 
muscular parts of the organ. 

Jt is obvious that the tongue is most copiously supplied 
with nerves. This probably accounts for the great 
facility of its motions, and the power of continuing 
them. 

* There is a very interesting paper on this subject, in the Me 
moirs of the Academy of Sciences for the year 1718, by Jussieu j 
jn which he describes the case of a female, fifteen years old, ex- 
amined by himself, who was born without a tongue. In this paper 
he refers to another case, described by Rolland, a surgeon of Sau- 
?nui', of a boy nine years old, whose tongue was destroyed by gan- 
grene. In each of these cases the subject was able to articulate 
very well, with the exception of a few letters : and also enjoyed the 
sense of taste„ 



^SKft 



CHAPTER III. 

OF THE THKOAT. 

To avoid circumlocution, tlie word throat is used 
as a general term to comprehend the structure which 
occurs behind the nose and mouth, and ahove the 
oesophagus and trachea. This structure consists, 

1st, Of the parts immediately behind the mouth, 
which constitute the Isthmus of the Fauces : 

2nd, Of the parts which form the orifice of the 
windpipe, or the Larynx ; — and 

3d, Of the muscular bag, which forms the cavity 
behind the nose and mouth that terminates in the 
oesophagus, or the Pharynx. 

SECTION I. 

I Of the Isthmus of the Fauces. 

In the back part of the mouth, on each side, are to 
be seen the two ridges or half arches, passing from 
the soft palate of the root of the tongue, mentioned in 
page 17? and said to be formed by plaits of the skin 
containing muscular fibres. The anterior plait, 
which contains the muscle called Constrictor Isthmi 
Faucium, passes directly from the side of the root of 
the tongue to the palate, and terminates near the 
commencement of the uvula. The posterior plait 
runs from the palate obliquely downwards and back- 
wards, as it contains the palato-pharyngeus muscle, 
which passes from the palate to the upper and pos- 
terior part of the tyroid cartilage. 

In the triangular space between these ridges is si- 
tuated a glandular body, called the Tonsil Amyg- 



30 Tonsils. — Epiglottis, 

data. This gland has an oval form, its longest dia- 
meter extending from above downwards, its sur- 
face is rathe^convex, its natural colour is a pale red. 
On its surface are the large orifices of many cells of 
considerable size, which exist througl^out the gland. 
These cells often communicate with each other, so 
so tjjat a probe can be passed in at one orifice and 
out at the other. 

Into these cells open many mucous ducts, which 
discharge the mucus of the throat, for the purpose of 
lubricating the surface, and facilitating the transmis- 
sion of food. 

The epiglottis, or fifth cartilage of the larynx, is 
situated at the root of the tongue, in the middle, be- 
tween the tonsils. The part vt^hich is in sight is 
partly oval in form, and of a whitish colour. Its po- 
sition, as respects the tongue, is nearly perpendicu- 
lar, and its anterior surface rather convex. 

The membrane continued from the tongue over the 
epiglottis is so arranged that it forms a plait, which 
extends from the middle of the root of the tongue 
along the middle of the anterior surface of the epi- 
glottis, from its base upwards. 

On each side of this plait, or frsenum, at the junc- 
tion of the surfaces of the tongue and of the epiglot- 
tis, there is often a depression, in which small por- 
tions of food sometimes remain ; and a small frsenum, 
similar to that above descril)ed, is sometimes seen on 
the outside of each of these cavities. 

The epiglottis is situated immediately before the 
opening into the larynx. 

The above descrii3ed parts can be well ascertained 
in the living subject, by a person who has a general 
knowledge of the structure. Thus, looking into the 
mouth, with the tongue depressed, the uvula and soft 
palate are in full view above, and the epiglottis is 
very perceptible below ; while the two ridges or la- 



Of the Larynx. 31 . 

teral half arches can be seen on each side, with the 
tonsil between them. 

SECTION II. 

Of the Larynx, 

In this structure are five cartilages, upon wliicb its 
form and strength depends, viz. the Cricoid^ the 
Thyroid^ the two Arytenoid^ and the Epiglottis, 
These cartilages are articulated to each other, and 
are supplied with muscles by which certain limited 
motions are effected. 

The basis of the structure is a cartilaginous ring, 
called the cricoid cartilage, which may be considered 
as the commencement of the windpipe. 

It may be described as an irregular section of a 
tube : its lower edge, connected witli the windpipe, 
being nearly horizontal when the body is erect; and 
the upper edge very oblique, sloping from before, 
backwards and upwards: in consequence of this, it 
has but little depth before, but is eight or nine lines 
deep behind. 

The Thyroid cartilage is a single plate, bent in 
such manner that it forms an acute angle with two 
similar broad surfaces on each side of it. It is so 
applied to the cricoid cartilage, that the lower edge 
of the angular part is at a small distance above the 
front part of that cartilage, and connected to it by 
ligamentous membrane: while its broad sides are ap- 
plied to it laterally, and thus partially inclose it. 

The upper edge of the angular part of the thyroid 
cartilage forms a notch ; and the natural position of 
the cartilage is such, that this part is very promi- 
nent in the neck ; it is called the Pomum Adami. 

Both the uppt^r and lower edges of the thyroid 
cartilage terminate posteriorly in processes, which 



32 Arytenoid Cartilages and Ligaments. 

are called Cornua. The two uppermost are longest ; 
they are joined by ligaments to the extremities of the 
OS hyoides. The lower and shorter processes are 
fixed to the cricoid cartilage. The thyroid cartilagCj 
therefore, partly rests upon the cricoid cartilage be- 
low, and is attached to the os hyoides above. It is 
influenced by the muscles which act upon the os 
hyoides, and also by some muscles which are in- 
serted into itself. It is moved obliquely downwards 
and forwards, in a slight degree, upon the cricoid 
cartilage by a small muscle, the crico-thyroideus, 
which arises from that cartilage and is inserted into it. 

The Arytenoid cartilages are two small bodies of 
a triangular pyramidal form, but slightly curved 
backwards. They are placed upon the upper and 
posterior edge of the cricoid cartilage, near to each 
other ; and their upper ends, taken together, resem- 
ble the mouth of a pitcher or ewer; from which cir- 
cumstance their name is derived. Their bases are 
broad ; and on their lower surfaces is a cavity, which 
corresponds with the convex edge of the cricoid car- 
tilage, to which they are applied. At these places, 
a regular moveable articulation is formed, by a cap- 
sular ligament between each of these cartilages and 
the cricoid, in consequence of which they can be in- 
clined backward or forward, inward or outward. 

From the anterior part of each of these cartilages, 
near the base, a tendinous cord passes forward, in a 
direction which is horizontal when the body is erect, 
to the internal surface of the angle of the thyroid. 
These ligaments are not perfectly parallel to each 
other; for they are nearer before than beiiiud. The 
aperture between them is from two to five lines wide 
when the muscles are not in action ; and this aperture 
is the orifice of the windpipe : for the exterior space, 
between these ligaments and the circumference of 
the thyroid, is closed up by membrane and rau«cle. 



Epiglottis. 33 

At a small distance above these ligaments are two 
others, which also pass from the arytenoid to the 
thyroid cartilages. They are not so tendinous and 
distinct as the first mentioned, and cannot be drawn 
so tense by the muscles of the arytenoid cartilages. 
They are also situated at a greater distance from 
each other, and thus form a large aperture. 

On the external side of the upper extremity of 
each of the arytenoid cartilages, and nearly in con- 
tact with it, is a small cartilaginous body, not so 
large as a grain of wheat, and nearly oval in form. 
These are connected firmly to the arytenoid carti- 
lages, and are called their appendices. Being in 
the margin of the aperture of the larynx, they have 
an effect upon its form. 

The arytenoid cartilages are the posterior parts 
of the larynx : the Epiglottis, which has already 
been mentioned, is the anterior. When this carti- 
lage is divested of its membrane, it is oval in its 
upper extremity, and rather angular below, termi- 
nating in a long narrow process, which is like the 
stalk of a leaf. It is firmly attached to the internal 
surface of the angular part of the thyroid by this 
lower process ; and, being placed in a perpendicu- 
lar position, one of its broad surfaces is anterior 
towards the tongue, and the other posterior, towards 
the opening of the windpipe. 

It is attached to the os hyoides by dense cellular 
texture or ligament, and to the tongue by those plaits 
of the membrane of the mouth, which have been 
already described. 

It is elastic, but more flexible than the other car- 
tilages; being somewhat different in its structure. — 
Its surface is perforated by the orifices of many 
mucous ducts. 

There is a small space between the lower part of 
this cartilage, and the upper part of the thyroid and 

Vol. II. 5 



34 Rima Glottidis.-— Glottis. 

the ligamentous membrane passing from it to the os 
hyoides. [n this is a substance, which appears to 
consist of glandular and of adipose matter. It is 
supposed that some of the orifices on the lower part 
of the epiglottis communicate with this substance. 

In the erect position of the body, the epiglottis is 
situated rather higher up than the arytenoid cartila- 
ges, and at the distance of ten or twelve lines from 
them. 

The membrane which covers the epiglottis, is ex- 
tended from each side of it to the arytenoid cartila- 
ges ; and being continued into the cavity of the la- 
rynx, as well as upon the general surface of the 
throat, it is necessarily doubled : this doubling forms 
the lateral margins of the orifice of the cavity of the 
larynx. In these folds of the membrane are seen 
very delicate muscular fibres, called the ArytenO' 
epiglottidei. 

The membrane continues down the cavity of the 
larynx, and, covering the upper ligaments, pene- 
trates into the vacuity between them and the lower 
ligaments, so as to form a cavity on each side of the 
larynx, opening between the two ligaments, which 
is called the Ventricle of Morgagni. The shape of 
these cavities is oblong. Its greatest length extends 
from behind forward, on each side of the opening 
into the windpipe formed by the two lower or prin- 
cipal ligaments ; so that when the larynx is removed 
from the subject, upon looking into it from above, 
you perceive three apertures : one in the middle, 
formed by the two lower ligaments ; and one on 
each side of it, between the lower and upper liga- 
ment, which is the orifice of the ventricle of Mor- 
gagni. 

The aperture between the two lower ligaments is 
called the Rima Glottidis, or Chink of the Glottis ; 
the upper aperture, formed by the fold of the mem- 



Arteries and JVerves of the Larynx. 35 

brane extending from the epiglottis to the arytenoid 
cartilages, may be termed Glottis. 

If the windpipe is divided near the larynx, and 
the larynx inverted, so that the rima glottidis may 
be examined from below, the structure appears still 
more simple : it resembles a septum fixed abruptly 
in the windpipe, with an aperture in it of the figure 
of the rima glottidis. 

The anterior surface of the two arytenoid carti- 
lages is concave. This concavity is occupied in 
each by a glandular substance, which lies between 
the cartilage and the lining membrane ; and extends 
itself horizontally, covered by the upper ligament 
of the glottis. The nature of these bodies is not 
perfectly understood ; but they are supposed to se- 
crete mucus. 

The membrane, which lines the cavity of the 
glottis being continued from the mouth and throat, 
resembles the membranes which invest those parts. 
In some places, where it is in close contact with the 
cartilages, it appears united with the perichondrium, 
and acquires more firmness and density. 

The general motions of the larynx are very intel- 
ligible to those who are acquainted with the muscles 
which are connected with the thyroid cartilage, and 
which move the os hyoides. They take place par- 
ticularly in deglutition, and in some modifications of 
the voice ; and also in vomiting. 
. The motions of the particular cartilages on each 
other can also be well understood, by attending to 
the origin and insertion of the various small muscles 
connected with them. The most important of these 
muscles are the crico-arytenoidei postici and later- 
ales, the thyreo-arytenoidei, the arytenoidei obliqui, 
and the arytenoideus transversus. The cftects of 
their actions appear to be the dilating or contracting 



36 virteries and A'*i^rves of the Larynx. 

the riina glottidis, and relaxing or extending the li- 
gaments which form it. 

The arteries of the larynx are derived from two 
sources, viz. the superior thyroid, or laryngeal 
branch of the external carotid ; and the thyroid 
branch of the subclavian. 

The nerves of the larynx also come to it in two 
very diiferent directions on each side. It receives 
two branches from the par vagum: one which leaves 
that nerve higli up in the neck, and is called the 
Superior La?yngeal branch ; and another which 
proceeds from it after it has passed into the cavity 
of the thorax, and is called from its direction the 
J^ecurrent. 

The extreme irritability of the glottis is unequivocally 
demonstrated by the cough which is excited when a 
drop of water, or any other mild liquid, or a crumb 
of bread enters it. Notwithstanding this, a flexible 
tube, or catheter, has several times been passed into 
the windpipe through the rima glottidis, and been 
endured by the patient a considerable time. 

The cough, which occurs when these parts are irritat- 
ed, does not appear to arise exclusively from the 
irritation of the membrane within the glottis ; for, if 
it were so, mucilaginous substances, when swallowed 
slowly, could not suspend it. Their effect in reliev- 
ing cough is universally known ; and as they are 
only applied to the surface exterior to the glottis, it 
is evident that the irritation of this surface must also 
produce coughing. 

Several curious experiments have been made to deter- 
mine the effect of dividing the different nerves which 
go to the larynx ; by which it appears that the re- 
current branches supply parts which are essentially 
necessary to the formation of the voice, whilst the 
laryngeal branches supply parts which merely in- 
fluence its modulation, or tone. See Mr. Haigh- 
ton's Essay on this subject : Memoirs of the Medic^tl 
Society of London, Vol. III. 



The Thyroid Gland.^The Pharynx. 37 

The Thyroid Gland 

May be described here, although a part of it is 
situated below the larynx. 

This body consists of two lobes, which are united 
at their lower extremities by a portion which extends 
across the anterior part of the windpipe. Each lobe 
generally rises upwards and backwards from the se- 
cond cartilaginous ring ©f the windpipe over the 
cricoid cartilage and a portion of the thyroid. It 
lies behind the sterno-hyoidei and sterno-thyroidei 
muscles. It is of a reddish brown colour, and appears 
to consist of a granulous substance ; but its ultimate 
structure is not understood. It is plentifully sup- 
plied with blood, and receives two arteries on each 
side : one from the laryngeal branch of the external 
carotid : and the other from the thyroid branch of 
the subclavian. 

Notwithstanding this large supply of blood, there 
is no proof that it performs any secretion ; for al- 
though several respectable anatomists have supposed 
that they discovered excretory ducts passing to the 
windpipe, larynx, or tongue, it is now generally 
agreed that such excretory ducts are not to be found. 
Several instances have however occurred, in which 
air has been forced, by violent straining, from the 
windpipe into the substance of this gland.* 

* There are two membranous expansions in the neck which 
should be noticed in its dissection. The first called Fascia Superfi- 
cialis lies immediately beneath the skin, may be considered as a 
continuation of the fascia superficialis abdominis, and is strongly 
connected to the base of the lower jaw, being also spread over the 
parotid gland. It is not very distinct in all subjects. The second 
is called the Fascia Profunda Cervicis ; it extends from the larynx 
and thyroid gland to the upper part of the sternum and first ribs, 
the great vessels, &c. of the superior mediastinum are placed im- 
mediately below it. — Ed. 



38 Structure of the Pharynx. 

SECTION III, 

Of the Pharynx. 

The pharynx is a large muscular bag, which 
forms the great cavity behind the nose and moutii 
that terminates in the oesophagus. 

It has been compared to a funnel, of which the 
cEsophagus is the pipe ; but it differs from a funnel 
in this respect, that it is incomplete in front, at the 
part occupied by the nose and mouth and larynx. 

It is connected above, to the cuneiform process of 
the occipital bone, to the pterygoid processes of the 
sphenoidal, and to both the upper and lower maxil- 
lary bones. It is in contact with the cervical vertebrae 
behind ; and, opposite to the cricoid cartilage, it ter- 
minates in the oesophagus. 

If the pharynx and oesophagus be carefully dis- 
sected and detached from the vertebrae, preserving 
the connexion of the pharynx with the head ; and 
the head then be separated from the body, by di- 
viding the articulation of the atlas and the os occi- 
pitis, and cutting through the soft parts below the 
larynx ; the resemblance to a funnel will be very 
obvious. 

In this situation, if an incision be made from above 
downwards through the whole extent of the poste- 
rior part of the pharynx, the communication of the 
nose, mouth, and windpipe, with this cavity, will be 
seen from behind at one view. 

The openings into the nose, or the posterior nares, 
appear uppermost. Their figure is irregularly oval 
or oblong : they are separated from each other by a 
thin partition, the vomer. Immediately behind, on 
the external side of each of these orifices, is the 
Eustachian tube. 

The soft palate will appear extending from the 
lower boundary of the posterior nares, obliquely 



Structure of the Pharynx. 39 

backwards and do\vnwards, so as nearly to close 
the passage into the mouth. The uvula hangs from 
it ; and, on each side of the uvula, the edge of the 
palate is regularly concave. 

Below the palate, in the isthmus of the fauces, 
are the ridges or half-arches, and the tonsils between 
them. The half-arch which presents first, in this 
view, runs obliquely downward and backward, and 
not parallel to the other. 

Close to the root of the tongue is the epiglottis 
erect ; and, immediately adjoining it, is an aperture 
large enough to admit the end of a middle-sized 
finger. This aperture is widest at the extremity 
next to the epiglottis, and rather narrower at the 
other extremity : it is the glottis or opening of the 
windpipe. When the larynx is elevated, the epi- 
glottis can be readily depressed so as to cover it 
completely. 

The extremities of the arytenoid cartilages, and 
their appendices, may be recognised at the posterior 
edge of the glottis. At a short distance below this 
edge, the oesophagus begins. 

The Pharynx is composed of the membrane con- 
tinued from the nose and mouth internally, and of 
a stratum of muscular fibres externally. The in- 
ternal membrane is very soft and flexible, and per- 
forated by many muciferous ducts. The surface 
which it forms is rather rough, owing to the mucous 
glands which it covers. It has a red colour, but 
not so deep as that of some other parts. It is con- 
nected to the muscular stratum by a loose cellular 
membrane. 

The muscular coat consists of three different por- 
tions, which are considered as so many distinct 
muscles. 

The fibres of each of these muscles originate on 
each side, and run in an oblique direction to meet in 



40 Structweof the Pharynx. 

the middle, thus forming the posterior external sur- 
face of the dissected pharynx. 

The fibres of the upper muscle originate from the 
cuneiform process of the occipital bone, from the 
pterygoid processes of the os sphenoides, and from 
the upper and lower jaws, near the last dentes mo- 
lares, on each side. They unite in a middle line in 
the back of the pharynx. 

The fibres of the middle muscle originate princi- 
pally from the lateral parts of the os hyoides, and 
from the ligaments which connect that bone to the 
thyroid cartilage. The superior fibres run obliquely 
upwards, so as to cover a part of the first mentioned 
muscle, and terminate in the cuneiform process of 
the occipital bone ; while the other fibres unite with 
those of the opposite side in the middle line. 

The fibres of the lower muscles arise from the 
thyroid and the cricoid cartilages, and terminate 
also in the middle line. Those which are superior, 
running obliquely upwards ; the inferior, nearly in a 
transverse direction. 

It is obvious, from the origin and insertion of 
these fibres, that the pharynx must have the power 
of contracting its dimensions in every respect ; and, 
particularly, that its diameter may be lessened at 
any place ; and that the whole may be drawn up- 
wards. 



SYSTEM OF ANATOMY 
PART VII. 



OF THE THORAX, 



Before the thorax is described, it will be in or- 
<ler to consider the 

Mammae ; 

Or those glandular bodies, situated on the anterior 
part of it, which, in females, are destined to the se- 
cretidn of milk. 

These glands lie between the skin and the pecto- 
ral muscles, and are attached to the surfaces of 
those muscles by cellular membrane. 

They are of a circular form ; and consist of a 
whitish firm substance, divisible into small masses 
or lobes, wliich are composed of smaller portions or 
lobuli. Between these glandular portions a great 
deal of adipose matter is so diffused, that it consti- 
tutes a considerable part of the bulk of the mammse. 

The gland however, varies greatly in thickness in 
the same person at different periods of life. 

The mammse become much enlarged about the 
age of puberty. They are also very large during 
pregnancy and lactation ; bul after the period of 
child bearing, they diminish considerably. They 
are supplied with blood by the external and internal 

YoL. II. 6 



42 Mammsc. 

mammary arteries, the brandies of wliicli enter 
them itregularly in several different places. 

The veins correspond with the arteries. 

From the small glandular portions that compose 
the mamma, fine excretory tubes arise, which unite 
together and form the great lactiferous ducts of the 
gland. These ducts proceed in a radiated manner 
from the circumference to the centre, and terminate 
on the surface of the nipple.* 

They are commonly auout fifteen in number, and 
vary considerably in size : the largest of them be- 
ing more than one-sixth of an inch in diameter. 

1 hey can be very readily injected by the orifices 
of tlie nipple, from a pipe filled with mercury, in 
subjects who have died during lactation or preg- 
nancy ; but they are very small in subjects of a dif- 
ferent description. 

It has been asserted, by respectable anatomists, 
that these ducts communicate freely with each other ; 
but they do not appear to do so : each duct seems to 
be connected with its proper branches only.f 

Haller appears to have entertained the remarka- 
hie sentiment, that some of the ducts originated in 
the adipose matter about the gland, as well as in the. 
glandular substance.^ 

The papilla, or nipple, in which these ducts ter- 
minate, is in the centre of the mamma : it consists of 
a firm elastic substance, and is nearly cylindrical in 
form. It is rendered tumid by irritation, and by 
certain emotions. 

The lactiferous ducts terminate upon its extremi- 
ty. When it is elongated they can freely discharge 

* Described in the ^6th century, by Charles Etienvie, Veralius and 
Posthuis, but their uses were unknown. — Ed. 

t See Edinburg Medical Commentaries, vol. l.page 31 — a paper 
by Meckel.--ED. 

± Elementa Physiologic Tom. 7, Pars 11, page 7. 



> 



Mannnse. 43 

their contents ; but when it contracts, this discharge 
is impeded. 

The skin immediately around the nipple is of a 
bright red colour in virgins of mature age In 
pregnant women it is sometimes almost black ; and 
in women who have borne children it is often brown- 
ish. It abounds with sebaceous glands, which form 
small eminences on its surface. 

This gland exists in males, although it is very 
small. In boys, soon after birth, it has often been 
known to tumefy and become very painful, in conse- 
quence of the secretion and accumulation of a whitish 
fluid, which can be discharged by pressure. It also 
sometimes swells and is painful, in males at the age 
of puberty. 

There have been some instances in which it has 
secreted milk in adult males ; and a few instances 
also in which it has been affected with cancer, in the 
same sex. 

The mamma is plentifully supplied with absorbent 
vessels, which pass from it to the lymphatic glands 
in the axilla. 

Its nerves are principally derived from the great 
plexus formed by the nerves of the arm. 



CHAPTER L 

OF THE GENERAL CAYITY OF THE THORAX. 
SECTION I. 

Of the form of the Cavity of the Thorax. 

The osseous structure of the thorax is describett 
in vol, I. page 94. The cavity is completed by the 
Intercostal muscles, which close the vacuities be- 
tween the ribs ; and by the diaphragm, which fills 
up the whole space included within its lower margin. 

If we except tlie apertures of the diaphragm, 
which are completely occupied by the aorta, the 
vena cava, and the oesophagus, &c. the only outlet 
of this cavity is above : it is formed by the upper 
ribs, the first dorsal vertebra, and the sternum. The 
figure of this aperture is between that of the circle 
and the oval; but it is made irregular by the verte- 
bra, and by the upper edge of the sternum. 

When the superior extremities and the muscles 
appropriated to them are removed, the external figure 
of the thorax is conical; but the cavity formed by it 
is considerably influenced by the spine, which pro- 
trudes into it ; while the ribs, as they proceed from 
the spine, curve backwards, and thus increase its 
prominency in the cavity. 

The diaphragm has a great effect upon the figure 
of the cavity of the thorax. It protrudes into it from 
below, with a convexity of such form that it has been 
compared to an inverted bowl ; so that, although it 
arises from the lower margin of the thorax, the cen 
tral parts of it ar§ nearly as high as the fourth rib. 



Pleurse. 45 

The position of the diaphragm is also oblique. 
The anterior portion of its margin, being connected 
to the seventh and eighth ribs^ is much higher than 
the posterior portion, which is attached to the 
eleventh and twelfth. 

In consequence of the ^^wre and y?052h'on of the 
diaphragm, the form of the cavity of the thorax re- 
sembles that of the hoof of the ox when its posterior 
part is presented forwards. 

SECTION II. 

Of the arrangement of thePleurm. 

The thorax contains the two lungs and heart, as 
well as several very important parts of smaller size. 

The lungs occupy the greatest part of the cavity ; 
and to each of them is appropriated a complete sac, 
called Pleura, which is so arranged that it covers 
the surface of the lungs, and is continued from it to 
the contiguous surface of the thorax, which it lines. 
After covering the lung, it is extended from it to the 
spine posteriorly, and the sternum anteriorly: so 
that in tracing the pleura in a circular direction, if 
you begin at the sternum, it proceeds on the inside 
of the ribs to the spine ; at the spine it leaves the 
surface of the thorax, and proceeds directly forwards 
towards the sternum. In its course from the spine 
to the sternum, it soon meets with tiie great branch 
of the windpipe and the blood vessels, vi^hich go to tlie 
lung : it continues on these vessels and round the 
lung until it arrives at the anterior side of the ves- 
sels, when it again proceeds forwards until it arrives 
at tlie sternum. Each sac being arranged in the 
same way, tiiere is a part of each extended from the 
spine to the sternum. These two laminai form the 
great vertical septum of the tliorax, called Mediasti 
num. They are situated at some distance from each 



4-6 Mediastinum, 

other ; and the heart, with its investing membrane or 
pericardium, is placed between them. 

The pericardium is also a complete sac or blad- 
der, which, after covering perfectly the surface of 
the heart, is extended from it so as to form a sac, 
which lies loose about it, and appears to contain it. 
This loose portion adheres to those parts of the la- 
minae of the mediastinum with which it is contigu- 
ous ; and thus three chambers are formed within the 
cavity of the thorax : one for each lung, and one for 
the heart. 

The two laminae of the pleura, which constitute 
the mediastinum, are at different distances from each 
other, in different places. At the upper part qf the 
thorax, they approach each other from the internal 
edges of the first ribs ; and, as these include a space 
which i.4 nearly circular, the vacuity between these 
laminae is necessarily of that form, at its commence- 
ment above. 

Here therefore is a space between them above, 
which is occupied by the great transverse vein that 
carries the blood of the left subclavian and the left 
internal jugular to the superior cava ; by the trachea ; 
by the oesophagus ; and by the subclavian and caro- 
tid arteries, as they rise from the curve of the aorta. 
This space is bounded below by the above mention- 
ed curve of the aorta. 

The heart and pericardium are so placed that 
there is a small distance between them and the ster- 
num : in this space the two laminse of the mediasti- 
num are very near to each other ; and cellular sub- 
stance intervenes between them. This portion of 
the mediastinum is called the Anterior Mediastinmn. 

Posteriorly, the heart and pericardium are also at 
a small distance from the spine ; and here the lami- 
nse of the mediastinum are at a greater distance from 
each other, and form a long narrow cavity which 



Preparation of the Thorax. 47 

extends down the thorax in front of the vertebrae : 
this is called the Posterior Mediastinum. It con- 
tains a considerable portion of the aorta as it des- 
cends from its curve, the cesophagus, the thoracic 
duct, and the vena azygos. The aorta is in contact 
with the left lamina, and can ofteii be seen through 
it when the left lung is lifted up. 

The oesophagus, is in contact with the right lami- 
mina : in its progress downwards, it inclines to the 
left side and is advanced before the aorta. 

The vena azygos appears posterior to the oesopha- 
gus ; it proceeds upwards until it is as high as the 
right branch of tlie windpipe : here it bends forward, 
round that branch, and opens into the superior cava, 
before that vein opens into the right auricle. 

The thoracic duct proceeds upwards from below^ 
lying in the space between the aorta and the vena 
azygos, until the beginning of the curve of the aorta, 
when it inclines to the left, proceeding towards the 
place of its termination. 

The formation of the mediastinum, and the arrange- 
ment of the pleura, as well as the connexion of these 
membranes with the parts contained in the thorax, 
may be studied advantageously, after the subject 
has been prepared in the manner now to be de- 
scribed. 

Take away, from each side, the five ribs which arc 
situated between the first and last true ribs, by se- 
parating their cartilages from the sternum, and their 
heads from the spine ; so that the great cavities of 
the thorax may be laid open. 

The precise course of the mediastinum is thus rendered 
obvious; and the sternum may now be divided with 
a saw throughout its whole length in the same di- 
rection ; so that the division of the bone may cor- 
respond with the space between the laminffi of the 
mediastinum. 

(Separate the portion of the sternum cautiously, so as 



48 Preparation of the Thorax, 

to avoid lacerating the laminae of mediastinum ; and 
keep them separate, while the trachea is dissected 
from the neck into the cavity of the thorax ; the 
great transverse vein and the descending cava are 
dissected to the pericardium ; and the left carotid 
artery, with the right subclavian and carotid, are 
dissected to the curve of the aorta, taking care not 
to destroy the laminae of the mediastinum. 

After this preparation the upper space between the 
laminae of the mediastinum can be examined ; and 
the relative situation of the trachea and the great 
vessels in it can be understood. The anterior me- 
diastinum can also be studied : the root of each lung, 
or its connexion with the mediastinum, may be seen 
perfectly ; and the precise situation of the lung, in 
its proper cavity, may be well conceived. 

After this, Avhile the portions of the sternum are sepa- 
rated, the pericardium may be opened, and the 
heart brought into view : the attachment of the pe- 
ricardium, and to the mediastinum, and to the dia- 
phragm, may be seen with advantage in this situa- 
tion. The portions of the sternum may now be 
detached from the ribs, with w^hich they remain 
connected ; and further dissection may be performed 
~ to examine the posterior mediastinum and its con- 
tents, and the parts which constitute the roots of the 
luDgs. 



CHAPTER II. 



OF THE HEART AND THE PEmCAUDIUM, AND THE GREAT 
VESSELS CONNECTED WITH THE HEART. 



SECTION II. 

Of the Pericardium. 

The heart is inclosed by a membranous sac, 
which, upon a superficial view, seems (mly con- 
nected with its great vessels ; but which, in fact, ad- 
heres closely to the whole of its surface. From this 
surface it is extended to those vessels ; from which 
it proceeds, after the manner of the reflected mem- 
branes, and forms an inclosure that lies loosely about 
the heart. If it were dissected from the heart, with- 
out laceration or wounding, it would be an entire 
sac. 

The pericardium, thus arranged, is placed be- 
tween the two laminse of the mediastinum, and ad- 
heres firmly to them where they are contiguous to it : 
it also adheres firmly to the diaphragm below, and 
thus preserves the heart in its proper position. 

The figure of the pericardium, when it is dis- 
tended, is somewhat conical ; the base being on the 
diaphragm. The cavity formed by it is larger than 
the heart after death, but it is probable that the heart 
nearly fills it during life; for, when this organ is 
distended by injection, it often occupies the whole 
cavity of the pericardium. 

The pericardium is composed of two laminse, the 
internal of which covers the heart, as has been al- 
ready described ; while the external merely extends 
over the loose portion of the other, and blends itself 

Vol. II. 7 



50 Of the Heart, 

with the mediastinum, where that membrane invests 
the great vessels. 

The internal surface of the pericardium is very 
smooth and polished ; and in the living subject is 
constantly moistened with a fluid, which is probably 
efliised from the exhalent vessels on its surface. 

The quantity of this fluid does not commonly ex- 
ceed two drachms ; but in cases of disease it some- 
times amounts to many ounces.* It is naturally 
transparent, but slightly tinged with red in children, 
and yellow in old persons. It is often slightly tinged 
with red in persons who have died by violence. 

SECTION II. 

Of the Heart. 

The great organ of the circulation consists of mus- 
cular fibres, which are so arranged that they give it 
a conical form, and compose four distinct cavities 
within it. 

Two of these cavities, which are called JluricleSf 
receive the contents of the veins ; the other two com- 
municate with the arteries, and are called Ventricles, 

The auricles form the basis of the cone ; the ven- 
tricles the body and apex. 

The structure of the auricles is much less firm 
than that of the ventricles, and consists of a smaller 
proportion of muscular fibres. They appear like 
appendages of the heart, while the ventricles com- 
pose the body of the viscus. 

The ventricles are very thick, and are composed 
of muscular fibres closely compacted, 

* The pericardium has been so distended, by effusion in dropsy, 
that it has formed a tumour, protruding on the neck from under 
the sternum. This tumour had a strong pulsating motion, It dis- 
appeared completely when the other hydropic symptorns weye re- 
lieved. 



Connexions of the Heart. £^1 

The figure of the heart is not regularly conical % 
for a portion of it, extending from the apex to the 
base, is flattened ; and in its natural position^ this flat 
part of the surface is downwards. 

It is placed obliquely in the body ; so that its 
base presents backward and to the right, and its 
apex forward and to the left. 

Notwithstanding this obliquity, the terms right 
and left are applied to the different sides of the 
heart, and to the different auricles and ventricles ; 
althcmgh they might, with equal propriety, be called 
anterior and posterior. 

The two great veins, called Vense Cavse, which 
bring the blood from every part of the body, open 
into the right auricle from above and below; the 
right auricle opens into the right ventricle ; and from 
this ventricle arises the artery denominated Pulmo- 
nary^ which passes to the lungs. 

The Pulmonary veins, which bring back the blood 
from the lungs, open into the left auricle ; this au- 
ricle opens into the left ventricle; and from this 
ventricle proceeds the Aorta, or great artery, which 
carries blood to every part of the body. 

The heart is preserved in its position, 1st, by the 
venae cavse, which are connected to all the parts to 
which they are contiguous in their course; 2d, by 
the vessels which pass between it and the lungs, 
which are retained in a particular position by the 
mediastinum ; 3d, by the aorta, which is attached to 
the mediastinum in its course downwards, after 
making its great curve ; and 4th, by the pericardium, 
which is attached to the great vessels and to the 
mediastinum. By these different modes the basis of 
the heart is fixed, while its body and apex are per- 
fectly free from attachment, and only contiguous to 
the pericardium. 

The external surface of the heart, being formeij 



5S Right Auricle. 

by the pericardium, is very smooth : under this sur- 
face a large quantity of fat is often found. 

The two auricles are contiguous to each other at 
the base, and are separated by a partition which is 
common to both. 

The Right Auricle originates from the junction of 
the two vense cavse. These veins are united at some 
distance behind the right ventricle,* and are dilated 
anteriorly into a sac or pouch, which is called the 
Sinus, and extends to the right ventricle, to which it 
is united. 

The upper part of this pouch, or sinus, forms a 
point with indented edges, which is detached from 
the ventricle, and lies loose on the right side of the 
aorta. This point has some resemblance to the ear 
of a dog, from which circumstance the whole cavity 
has been called auricle ; but by many persons the 
cavity is considered as consisting of two portions : 
the Auricle, strictly speaking ; and the Sinus Veno- 
sus, above described : they however form but one 
cavity. 

This portion of the heart, or Right Auricle, is of 
an irregular oblong figure. In its posterior surface, 
it is indented ; for the direction of the two cavse, 
at their junction, is not precisely the same ; but they 
form an angle, which causes this indentation. The an- 
terior portion of the auricle, or that which appears like 
a pouch between the ventricle and the veins, is differ- 
ent in its structure from the posterior part, which is 
strictly a portion of the veins. It consists simply of 
muscular fibres, which are arranged in fasciculi that 
cover the whole internal surface : this is also the 
case with the point, or that part which is strictly 
called auricle. 

* In this description the heart is supposed to be in its natural 
position. 



Right Ventricle* 53 

These fasciculi are denominated Musculi Pecti- 
nati, from their resemblance to the teeth of a comb. 

That part of the internal surface, which is formed 
by the septum, is smooth ; and the whole is cover- 
ed by a delicate membrane. 

On the surface of the septum, below the middle, 
is an oval depression, which has a thick edge or 
margin : this is called the Fossa Ovalis. In the foe- 
tal heart, it was the Foramen Ovale, or aperture 
which forms the communication between the two 
auricles. 

Near this fossa is a large semilunar plait, or valve, 
with its points and concave edge uppermost, and 
convex edge downwards. It was described by Eu- 
stachius, and, therefore, is called the Valve of Eu- 
stachius. 

Anterior to this valve, and near the union of the 
auricle and ventricle, is the orifice of the proper vein 
of the heart, or the coronary vein. This orifice is 
covered by another semilunar valve, which is some- 
times reticulated. 

The aperture, which forms the communication be- 
tween the right auricle and right ventricle, is about 
an inch in diameter, and is called ostium veiiosum. 
From its whole margin arises a valvular ring, or du- 
plicature of the membrane lining the surface : this 
circular valve is divided into three angular portions, 
which are called Valvulse Tricuspides. From their 
margins proceed a great number of fine tendinous 
threads, which are connected to a number of distinct 
portions of muscular substance, which arise from the 
ventricle. 

The right Ventricle, when examined separately 
from the other parts of the heart, is rather triangular 
in its fiiijUre. It is composed entirely of muscular 
fibres closely compacted ; and is much thicker than 
the auricle, although not so thick as the other ven^ 



54 liight Ventricle. 

tricle. Its iniernal surface is composed of bundles 
or columns of fleshy fibres^ which are of various 
thickness and length. Some of those columns arise 
from the ventricle, and are connected with the ten- 
dinous threads, which are attached to the margin 
of the tricuspid valves : the direction of them is from 
the apex of the heart towards the base. Others of 
the columns arise from one part of the surface of the 
ventricle, and are inserted into another part. A third 
species are attached to the ventricle throughout their 
whole length, forming ridges or eminences on it. The 
columns of the two last described species are very nu- 
merous. They present an elegant reticulated surface 
when the ventricle is laid open, and appear also to 
occupy a considerable portion of the cavity of the 
heart, which some of them run across in every di- 
rection near the apex. They are all covered by a 
membrane continued from the auricle and the tricus- 
pid valves ; but this membrane ap[>€ars more delicate 
and transparent in the ventricle than itis in the au- 
ricle. 

A portion of the internal surface of the ventricle, 
which is to the left, is much smoother and less fasci- 
culated than the rest : it leads to the orifice of the 
pulmonary artery, which arises from it near^he ba- 
sis of the ventricle. This artery is very conspicuous, 
externally, at the basis of the heart. 

It is very evident, upon the first inspection of the 
heart, that the valvulse tricuspides will permit the 
blood to flow from the auricle to the ventricle ; but 
must rise and close the orifice, and thereby prevent 
its passage back again, when the ventricle contracts. 

The use of the tendinous threads, which connect 
the valves to the fleshy columns, is also very evi- 
dent; the valve is supported by this connexion, 
and prevented from yielding to the pressure and 
opening a passage into the auricle. The blood., 



Left Auricle, 55 

therefore, upon the contraction of the ventricle, is 
necessarily forced into the pulmonary artery ; the 
passage to which is now perfectly free. Into this 
artery the membrane lining the ventricle seems con- 
tinued ; but immediately within the orifice of the 
artery it is formed into three semicircular folds, 
each of which adheres to the surface of the artery 
by its circumference, while the edge constituting its 
diameter is loose. In the middle of this loose edge, is 
a small firm tubercle, called Corpusculum Arantii^^ 
which adds to the strength of the valve. Each of 
these valves, by its connexion with the artery, forms 
a sac or pocket, the orifice of which opens forward 
towards the course of the artery, and the bottom of 
it presents towards the ventricle. Blood will, there- 
fore, pass from the ventricle in the artery, and along 
it, without filling these sacs ; and on the contrary, 
in this course, will compress them and keep them 
empty. If it moves in the artery towards the hearty 
it will necessarily fill these sacs, and press the se- 
micircular portions from the sides of the artery 
against each other : by this means a partition, or sep- 
tum, consisting of three portions, will be formed be- 
tween the artery and the heart, which will always 
exist when the artery compresses (or acts upon) its 
contents. It is demonstrable, by injecting wax into 
the artery, in a retrograde direction, that these valves 
do not form a flat septum, but one which is convex 
towards the heart, and concave towards the artery ; 
and that this convexity is composed of three distinct 
parts, each of which is convex. At the place where 
these valves are fixed, the artery bulges out when 
distended by a retrograde injection. The enlarge- 
ments thus produced are called the Sinuses of Val- 
salvtty after the anatomist who first described them. 

* After ArantiuB, a professor at Bologna, who first described it^ 



56 Left Ventricle. 

The valves are called Semilunar; and, although 
they are formed by a very thin membrane, they are 
very strong. 

The Left Auricle is situated on tlie left side of the 
basis of the heart. It originates from the junction of 
the four pulmonary veins ; two of which come from 
each side of the thorax, and appear to form a large 
part of it. It is nearly of a cubic form ; but has also 
an angular portion, which constitutes the proper au- 
ricle, that proceeds from the upper and left part of 
the cavity, and is situated on the left side of the 
pulmonary artery. 

This auricle is lined by a strong membrane, from 
which the valves between it and the ventricle ori- 
ginate : but it has no fleshy columns or musculi pec- 
tin ati, except in the angular process properly called 
auricle. 

These valves, and the orifice communicating with 
the ventricle, resemble those which have been alrea- 
dy described between the right auricle and ventricle ; 
but with this difference, that the valvular ring is di- 
vided into two portions only, instead of three, which 
are called Valviilx Mitrales. The tendinous threads, 
which are connected to the muscular columns, are also 
attached to these valves, as in the case of the right 
auricle. 

These valves admit the passage of blood from the 
auricle into the ventricle, but completely prevent its 
return when the ventricle contracts. One of them is 
so situated that it covers the mouth of the aorta while 
the blood is flowing into the ventricle, and leaves 
that orifice open when the ventricle contracts, and 
the passage to the auricle is closed. 

The Left Ventricle is situated posteriorly, and to 
the left of the Right Ventricle : its figure is different, 
for it is rather conical, and it is also longer. 

The internal surface of this ventricle resembles 



Muscular Fibres of the Heart. 57 

that of the right ventricle ; but the columnse carnese 
are stronger and larger. 

On the right side of this ventricle is the mouth of 
the aorta. The surface of the ventricle near this 
opening is smooth and polished to facilitate tlie pas- 
sage of the blood. 

The mouth of the aorta is furnished with three 
semilunar valves, after the manner of the pulmonary 
artery, but the former are stronger ; the corpuscu- 
la arantii are better developed in them. Indeed Mr. 
Hunter does not admit of their existence in the pul- 
monary artery. The sinuses of valsalva are about 
the same size in both arteries. 

The cavity of this ventricle is supposed to be 
smaller than that of the right : but the amount of the 
difference has not been accurately ascertained. 

This ventricle must have much more force than 
the right, as its parietes are so much tliicker. Their 
thickness often exceeds half an inch. 

The difference in the strength of the two ventri- 
cles probably corresponds with the difference be- 
tween the extent of the pulmonary artery and the 
aorta. 

The thickness of the septum between the ventri- 
cles is thicker than the sides or parietes of the right 
ventricle, and less thick than those of the left. 

The muscular fibres of the heart are generally less 
florid than those of the voluntary muscles : they are 
also !nore closely compacted together. The direc- 
tion of many of them is oblique or spiral ; but this 
general arrangement is very intricate : it is such, 
however, that the cavities of the heart are lessened, 
and probably completely obliterated, by the contrac- 
tion of these fibres.* 

♦ Mr. Home has given a precise description of the muscular 
fibres of the heart in liis Croonian Lecture. London l*liilf)Sophica i 
Transactions for 1795, part. 1, page 215. 

Vol. it. 8 



58 Coronary Vessels, ^c. 

The external surface of the heart is covered by 
that portion of the pericardium which adheres to it. 
Adipose matter is often deposited between this mem- 
brane and the muscular surface ; being distributed 
irregularly in various places. 

This membrane is continued from the surface of the 
ventricles over that of the auricles. When it is dis- 
sected off from the place of their junction, these sur- 
faces appear very distinct from each other. 

The proper blood vessels of the heart appear to be 
arranged in conformity to the general laws of the 
circulation, and are very conspicuous on the surface. 
There are two arteries which arise fi'bm the aorta 
immediately after it leaves the heart, so that their 
orifices are covered by two of the semilunar valves. 
One of these passes from the aorta between the pul- 
monary artery and the right auricle, and continues 
in a circular course in the groove between the right 
auricle and the right ventricle, and sends off its prin- 
cipal branches to the right side of the heart. 

The other artery of the heart passes between the 
pulmonary artery and the left auricle. It divides into 
two branches : one, which is anterior, passes to a 
groove on the surface, corresponding to the septum 
between the two ventricles, and continues on it to 
the apex of the heart, sending off branches in its 
course ; another, which is posterior and circumflex, 
passes between the left auricle and ventricle. 

The great vein of the heart opens into the under 
side of the right auricle, as has been already men- 
tioned : the main trunk of this vein passes for some 
distance between the left auricle and ventricle.* 

* It was asserted by Vieussens at an early period, in the last 
centuT-y, and soon afterwards by Thebesius, a German Professor, 
that there were a numljer of small orifices in the textui-e of the 
heart, whicli opened into the different cavities on both sides of it. 

This assertion of a fact so difficult to reconcile with the general 
principles of the circulation, was received with great hesitation : 



» 



Wlie Great Vessels. 59 

From the course of these different vessels round 
the basis of the ventricles of the heart, tliey are ge- 
nerally called Coronary Vessels : the arteries are de- 
nominated, from their position, Right and Left Co- 
ronary. 

The nerves of the heart come from the cardiac 
plexus, which is composed of threads derived from 
the intercostal or great sympathetic nerves, and the 
nerves of the eighth pair. 

SECTION III. 

Of the Aorta, the Pulmonary Artery and Veins, 
and the Vense Cavae ,* at their commencement. 

The two great arteries, which arise from the heart, 
commence abruptly, and appear to be extremely dif- 
ferent in their composition and structure from the 
heart. 

They are composed of a substance, which has a 
whitish colour and very dense texture, and is very 
clastic as well as firm and strong. 

When the pericardium is removed, these arteries 
appear to proceed together from the upper part of 

and although it was confirmed by some very respectable anatomists 
of the last century, it was denied by others. Some of the anato- 
mists of the present day have denied the existence of these orifices, 
and some others have neglected them entirely. 

The subject has lately been brought forward in the London Phi- 
losop^hical Transactions for 1798, Part I, by a very respectable 
anatomist, Mr. Abei-nethy, who states that he has often passed a 
Course waxen injection from the proper arteries and veins of the 
heart into all the cavities of that organ, and particularly into the 
Left Ventricle. But it was only in subjects with diseased lungs 
that this luas practicable. 

The existence of this communication between tlie coronary ves- 
sels and the great cavities of the heart seems therefore to be proved. 
The easy demonstration in such subjects is ingeniously referred by 
Mr. Abernethy, to the obstruction of the circulation in the limgs: 
and he regards the communication as a provision enal)Hng the co- 
ronary vessels to unload themselves, when the coronary vein can- 
not dischai-ge freely into the right auricle. 



60 Pulmonary Artery and Veins and Venae Cavx. 

the basis of the heart : the pulmonary artery being 
placed to the left of the aorta with the left auricle on 
the left side of it, and the right auricle on the right 
side of the aorta. The pulmonary artery arises 
from tlje most anterior, and left part of the basis of 
t!ie right ventricle, and proceeds obliquely back- 
wards and upwards ; inclining gradually to the left 
side for about eighteen or twenty lines ; when it di- 
vides into two branches which pass to the two lungs. 

The aorta arises from the left ventricle, under the 
origin of the pulmonary artery, and immediately 
4)roceeds to the right, covered by that vessel, until 
it mounts up between it and the right auricle : it 
then forms a great curve, or arch, which turns back- 
ward and to the left, to a considerable distance be- 
yond the pulmonary artery. In this course, it cros- 
ses the right branch of the pulmonary artery ; and, 
turning down in the angle between it and the left 
branch, takes a position on the left side of the spine. 

The course of this artery, from its commencement 
at the ventricle, to the end of the great curve or arch, 
is extremely varied. 

The uppermost part of the curve is in the bottom 
of the chamber formed by the separation of the la- 
minsB of tise mediastinum when they join the first 
rib on each side. 

From this part of the curve three large branches 
go off, viz. one, which soon divides into the carotid 
and the subclavian arteries of the right side ; a se- 
cond, somewhat smaller, which is the left carotid ; 
and a third, which ^s the left subclavian artery. 

When the heart and its great vessels are viewed 
from behind, (after they have all been tilled with 
injection ; and the pericardium, mediastinum, and 
windpipe have been removed,) the aorta appears 
first, descending behind the other vessels ; the pul- 
monary artery then appears, dividing so as to form 



Pulmonary Artery and Veins and Vense Cavas. 6l 

an obtuse angle with its two great branches, each of 
which divides again before it enters tbe lung to 
wbich it is destined. 

Under the main trunk of the pulmonary artery is 
the left auricle : its posterior surface is nearly of a 
square form, and each of the pulmonary veins pro- 
ceeds from one of its angles. These veins ramify in 
the substance of the lungs, at a very short distance 
from the auricle : the two uppermost of them are si- 
tuated rather anterior to the branches of the pulmo- 
nary artery. 

In this posterior view, the pulmonary vessels of 
the right side cover a great part of the right auricle, 
as it is anterior to them. The lower portion of the 
auricle, with the termination of the inferior cava, is 
to be seen below them. Above them, the superior 
cava appears ; and in that part of it, which is imme- 
diately above the right branch of the pulmonary ar- 
tery, is the orifice of the vena azygos. 

In its natural situation in the thorax, the superior 
cava is connected by cellular membrane to the right 
lamina of the mediastinum, and supported by it. 
At a small distance below the upper edge of the 
sternum, it receives the trunk formed by the left sub- 
clavian and internal jugular vein which passes ob- 
liquely across the sternum below its inner edge, in 
the upper space between the laminae of the mediasti- 
num. 



CHAPTER III. 

OF THE TRACHEA AND THE LUNGS. 

Although the principal part of the windpipe is 
situated in the neck ahove the cavity of the thorax, 
it is so intimately connected with the lungs, that it is 
necessary to describe them together. 

SECTION I. 

Of the Trachea, 

Trachea is the technical name for the windpipe, 
or tube wliich passes from the larynx to the lungs. 

This tube begins at the lower edge of the cricoid 
cartilage, and passes down the neck in front of the 
fEsophagus as low as the third dorsal vertebra, when 
it divides into two branches called Bronchia^ one of 
which goes to the right and the other to the left lung 
and ramifies very minutely in them. 

Tliere is in its structure a number of flat cartila- 
ginous rings placed at small distances from each 
other, the edges of which are connected by mem- 
brane so that they compose a tube. 

These cartilaginous rings are not complete, for 
they do not form more than three-fourths or four- 
fifths of a circle ; but their ends are connected by a 
membrane which forms the posterior part of the tube. 

They are not alike in their size or form ; some of 
fhem are rendered broader than others, by the union 
of two or three rings with each other, as the upper- 
most. The lowermost also is broad, and has a form 
wliich is accommodated to the bifurcation of the tube. 
Their number varies, in different persons, from fif 
teen to twenty. 



Structure of the Trachea, 63 

These rings may be considered as forming a part 
of the first proper coat of the trachea ; which is com- 
posed of them, and of an elastic membrane that oc- 
cupies all the interstice between them ; so that the 
cartilages may be regarded as fixed in this membrane. 

A similar arrangement of rings exists in the great 
branches of the bronchia ; but after they ramify in 
the lungs, the cartilages are no longer in the form of 
rings : they are irregular in their figures, and are so 
arranged in the membrane that they keep the tube 
completely open. These portions of cartilage do 
not continue throughout the whole extent of the ra- 
mifications ; for they become smaller, and finally dis- 
appear, while the membranous tube continues with- 
out them, ramifying minutely, and probably forming 
the air cells of the lungs. 

This membrane is very elastic : the lungs are very 
elastic also ; and it is probable that their elasticity is 
derived from this membrane. 

On the inside of this coat of the trachea is an ar- 
rangement of muscular fibres, which may be called 
a muscular coat. It is best seen by peeling off or 
removing the internal coat to l)e next described. 

On the membranous part of the trachea, where the 
cartilaginous rings are deficient, these muscular fi- 
bres run evidently in a transverse direction : in the 
spaces between the cartilages their direction is lon- 
gitudinal. There is some reason to doubt whether 
these longitudinal fibres are confined altogether to 
the spaces between the cartilaginous rings, and at- 
tached only to their edges, because there is a fleshy 
substance on the internal surface of the rings, wliich 
appears to be continued from the spaces between 
them. 

The internal coat of the trachea is a thin and de- 
licate membrane, perforated with an immense num- 



64 Black Glands of the Bronchix. 

ber of small foramina^ which are the orifices of inii- 
cous ducts. 

On the surface of this membrane there is an ap- 
pearance of longitudinal fibres which are not distri- 
buted uniformly over it, but run in fasciculi in some 
places, and appear to be deficient in others. These 
fasciculi are particularly conspicuous in the ramifi- 
cations of the bronchia in the lungs. 

On the posterior membranous portion of the tra- 
chea, where the cartilages are deficient, a conside- 
rable number of small glandular bodies are placed, 
which are supposed to communicate with the mucous 
ducts that open on the internal surface. If these 
bodies are removed from the external surface of this 
portion, and the muscular fibres are also removed 
from the internal, a very thin membrane only re- 
mains, which is very different from that which is 
left between the rings, when the fleshy substance is 
removed from that situation. 

The reason of the deficiency in the rings, at this 
posterior part, is not very obvious.* It continues in 
the bronchia until the form of their cartilages is 
changed in the lungs: if it were only to accommo- 
date the oesophagus, during the passage of food, 
there would be no occasion for its extension to the 
bronchia. 

At the bifurcation of the trachea, and on the 
bronchia, are a number of black coloured bodies, 
which resemble the lymphatic glands in form and 
texture. They continue on the ramifications of the 
bronchia some distance into the substance of the 
lungs. Their number is often very considerable ; 
and they vary in size from three or four lines in dia- 

♦ Doctor Physick has advanced the opinion that it enables a person 
to expel the mucus of the lungs by contracting the size of the tra- 
chea, and consequently increasing the velocity or impetus of the 
air.- Ed. 



Root of the Lungs. 65 

meter to eighteen or twenty. As lymphatic vessels 
have been traced to and frou them during the r 
course to the thoracic duct, they are considered as 
lymphatic glands. 

SECTION II. 

Of the Lungs. 

Theue are two of these organs : each of which 
occupies one of the great cavities of the thorax. 

When placed together, in their natural position, 
they resemble the hoof of the ox, with its back part 
forward; but they are at such a distance from each 
other, and of such a figure, that they allow the me- 
diastinum and heart to intervene; and they cover 
every part of the heart anteriorly, except a small 
portion at the apex. 

Each lung fills completely the cavity in which it 
is phuied, and every part of its external surface is in 
contact with some part of the internal surface of the 
cavity ; but when in a natural and healthy state, it 
is not connected with any part except the laminae of 
the mediastinum. One great branch of the trachea 
and of the pulmonary artery pass from the medias- 
tinum to each lung, and enter it at a place which is 
rather nearer to the upper rib than to the diaphragm, 
and much nearer to the spine than the sternum : at 
this place also the pulmonary veins return from the 
lung to the heart. 

These vessels are inclosed in a membrane, which 
is continued over them from the mediastinum, and 
extended from them to the lung. Thus covered, 
they constitute what has been called the Hoot of the 
Lung. 

When their covering, derived from the mediasti- 
num, is removed, the situation of these vessels ap- 
pears to be such that the bronchia are posterior,. 

Vol. II. 9 



66 Colour of the Lungs. 

the branches of the pulmonary artery are rather 
above and before, and the veins below and before 
them. 

Each of these vessels ramifies before it enters into 
the substance of the lungs : t5ie bronchia and the 
branches of the pulmonary artery send each a large 
branch downward to the inferior part of the lungs, 
from which the lower pulmonary veins pass in a 
direction nearly horizontal. In general, each of the 
smaller ramifications of the bronchia in the lungs is 
attended by an artery and a vein. 

Each lung is divided, by very deep fissures, into 
portions which are called Lobes. The right lung is 
composed of three of these lobes, and the left lung 
of two. 

The lungs are covered, as has been already stated, 
■with the reflected portion of the pleura continued 
from the mediastinum, which is very delicate, and 
almost transparent. They have, therefore, a very 
smooth surface, which is kept moist by exudation 
from the arteries of the membrane. 

The Colow of the Lungs is different in different 
subjects. In children they are of a light red colour ; 
in adults they are often of a light gray ; owing to the 
deposition of a black pigment in the substance im- 
mediately under the membranes which form their 
external surface. Their colour is often formed by a 
mixture of red and black. In this case they are 
more loaded with blood, and the vessels of the in- 
ternal membranes being distended with it, the red 
colour is derived from them. 

The black pigment sometimes appears in round 
spots of three or four lines in diameter : under the 
external membrane it is often in much smaller por- 
tions, and sometimes is arranged in lines in the in- 
terstices of the lobuli, to be hereafter mentioned. 
Jt is also diffused in small quantities throughout the 
substance of the lungs. 



Structure of the Lungs. 67 

The source of this substance, and the use of it, 
are unknown. 

The lungs are of a soft spongy texture ; and, in 
animals that have breatliecl, they have always a 
considerable quantity of air in them. 

They consist of cells, which communicate with 
the branches of the trachea that ramify tlirough them 
in every part. These cells are extremely small, and 
the membranes which compose them are so thin and 
delicate that if they are all filled by an injection of 
wax, thrown into the trachea, the whole cellular 
part of the lung will appear like a mass of wax. If 
a corroded preparation be made of a lung injected 
in this manner with force, the wax will appear like 
a concretion. 

These effects of injections prove that the mem- 
branes of which the cells are formed are very thin ; 
and, of course, that their volume is very small when 
compared with the capacity of the cells. 

In those corroded preparations, in which the ra- 
mifications of the bronchia are detached from the 
wax of the cells, these ramifications become ex- 
tremely small indeed. 

If the lungs of the human subjects, or of animals 
of similar construction, be examined when they are 
inflated, their cellular structure will be very obvious, 
although, their cells are so small that they cannot 
commonly be distinguished by the naked eye. Each 
of the extreme ramifications of the bronchia appears 
to be surrounded by a portion of tiiis cellular sub- 
stance, which is gradually distended when air is 
blown into the ramification. 

This cellular substance is formed into small por- 
tions of various angular figures, which are denomi- 
nated Lohuli: these can be separated to a consider- 
able extent from each other, "^rhey are covered by 
the proper coat of the lungs, which is extremely de- 



68 Structure of the Lungs* 

licate, and closely connected to the general covering 
derived from the pleura. Between the lobuli, where 
they are in contact with each other, there is a por- 
tion of common cellular substance, which is easily 
distinguished through the membrane covering the 
lungs. This is very distinct from the cellular struc- 
ture which commsinicates with the ramifications of 
the bronchia, and contains air ; for it has no com- 
munication with the air, unless the proper coat of 
the lungs be ruptured. If a pipe be introduced by 
a puncture of the external coat of the lungs, and 
this interstitial cellular me nbrane be inflated, it will 
compress the lobuli. This cellular membrane is al- 
ways free from adipose matter : it may be easily ex- 
amined in the lungs of the bullock. 

Upon the membranes which compose the air cells, 
the pulmonary artery and vein ramify most minute- 
ly ; and it seems to have been proved within the last 
thirty years, by the united labours of chemists and 
physiologists, that the great object of respiration is 
to effect a chemical process between the atmospheric 
air, when taken into the air cells^ and the blood 
which circulates in these vessels. 

In addition to the blood vessels which thus pass 
through the substance of the lungs, there are several 
smaller arteries, denominated Bronchial, which 
arise either from the upper intercostal, or from the 
aorta itself: they pass upon the bronchia, and are 
distributed to the substance of the lungs. The veins 
which correspond with these arteries terminate ulti- 
mately in the vena azygos. 

The nerves of the lungs are small in proportion to 
the bulk of these organs. They are derived princi- 
pally from the par vagum and the intercostal nerves. 

The elasticity of the air cells of the lungs and of 
the ramificativms of the bronchia which lead to them, 
appears by their rapid contraction after distention, 



The Thorax of the Fcetus, 69 

and by the force with which they expel the air which 

is used to intiate them when taken out of the thorax. 

The Thorax of the Foetus. 

In the cavity between the laminse of the medias- 
tinum, where they approach each other from the first 
ribs, is situated a substance which is denominated 
the 

Thymus Gland, 

This substance gradually diminishes after birth, 
so that in the adult it is often not to be found : and 
when it exists it is clianged in its texture, being 
much firmer, as well as greatly diminished. 

In the fcBtus it is of a pale red colour ; and during 
infancy it has a yellowish tinge. It generally ex- 
tends from the thyroid gland, or a little below it, to 
the pericardium. From its superior portion two la- 
teral processes are extended upwards : below, it is 
formed into two lobes, which lie on the pericardium. 

If an incision be made into its substance, a fiuid 
can be pressed out, which has a whitish colour, and 
coagulates upon the addition of alcohol. 

Although it is called a gland, no excretory duct 
has ever been found connected with it. 

The blood vessels of this body are derived from 
the thyroid branches of the subclavians, from the in- 
ternal mammaries, and the vessels of the pericardium 
and mediastinum. 

The Heart, 

And the great arteries which proceed from it, have 
some very interesting peculiarities in the foetus. 

In the septum between the two auricles, is a fora- 
men of snflicient size to permit the passage of a large 
quill, which inclines to the oval form, with its 
longest diameter vertical when the body is erect. On 
the lift side of tlse septum, a valve, formed by rhc 
lining membranes, is connected to this foramen ; and 



70 The Thorax of the Foetus. 

allows a free passage to a fluid moving from the riglit 
auricle to the left, but prevents the passage of a fluid 
from the left to the right. This structure is evident- 
ly calculated to allow some of the blood which flows 
into the right auricle from the two venae cavse to 
pass into the left auricle of the heart, instead of 
going into the right ventricle. As the contents of 
the left auricle pass into the left ventricle, and from 
thence into the aorta, it is obvious that the blood, 
which passes from the right auricle into the left 
through this foramen, must be transmitted from the 
system of the vena cava to the system of the aorta 
without going through the lungs, as it must necessa- 
rily do in subjects who do not enjoy the foetal struc- 
ture. 

The Pulmonary Artery and the Aorta 

Have a communication in the foetus, which is very 
analogous to the communication between the auricles 
of the heart. 

From the pulmonary artery, where it divides into 
the two great branches, another large branch conti- 
nues, in the direction of the main trunk, until it joins 
the aorta ; with which it communicates at a small 
distance below the origin of the left subclavian artery. 
In the young subject that has never respired, it ap- 
pears as if the pulmonary artery was continued into 
the aorta, and sent off in its course, a branch on each 
side, much smaller than itself, to each lung. In 
subjects that have lived a few days, these branches 
to the lungs are much larger ; and then the main 
pulmonary artery appears to have divided into three 
branches : one to each lung, and one to the aorta ; 
but that which continues to the aorta is larger than 
either of the others. 

In the course of time, however, this branch of the 
aorta is contracted, so that no fluid passes through it ; 



General Observations. 71 

aud it has the appearance of a ligament, in which 
state it remains. 

The course of the hlood from the rii^ht ventricle, 
through the pulmonary artery, to the aorta below its 
curve, is more direct than that from the left ventricle 
to the same spot, through the aorta at its commence- 
ment. The column of blood in the aorta below its 
curve is evidently propelled by the force of both ven- 
tricles : and this circumstance, although it seems to 
proceed merely from the state of tiie foetal lungs, is 
particularly calculated for the very extensive circu- 
lation which the foetus carries on, by means of the 
umbilical arteries and vein in the placenta. 

The Lungs of the Foetus 

Differ greatly from those of the adult. They ap- 
pear solid, as if they were composed of the paren- 
chymatous substance which constitutes the matter of 
glands, rather than the light spongy substance of 
the lungs of adults. They differ also in colour from 
the lungs of older subjects, being of a dull red. 

They have greater specific gravity than water : 
but if air be once inspired, so much of it remains in 
them that they ever afterwards iloat in that fluid. 

The nature of the process of respiration, and its effects 
upon the animal economy, particularly upon the action 
of the heart, appear to be much better understood at 
this time than they were before the discovery of the 
composition of the atmosphere, by Dr. Priestly and 
by Mr. Scheele. The publications upon this subject, 
which have appeared since that period, viz. 1774, are 
therefore much more interesting to the student of me- 
dicine than those which preceded them. Two of these 
publications ought to be parti cularlj' noticed by him : 
viz. an essay, by Dr. Edward Goodwyn, intitled, ''The 
Connexion of life with respiration ;" and — the " Phy- 



7S Cases of Malformation. 

siological Researches of M. Bichat upon Lite and 
Death. Part Second.* 
The general doctrines respecting the oxygenation or de' 
carbonation of the blood, and the absolute necessity 
that it should take place to a certain degree in order 
to preserve life, are confirmed by a number of cases 
of malformation of the heart or the great vessels, in 
which the structure v?as such that a considerable por- 
tion of venous blood passed from the right side of the 
heart to the aorta, without going through the lungs. 
In these different cases, notwithstanding the structure 
was somewhat varied, the symptoms produced were 
very much alike ; differing in the respective patients 
in degree only, and not in kind. 

The symptoms indicating this structure are blu* 
colour of the face, (such as generally accompanies 
suffocation) extending more or less over the whole 
body, and particularly apparent under the nails of the 
fingers and toes ; anxiety about the region of the 
heart; palpitation; laborious respiration ; sensations 
of great debility, &c. : all of which are greatly ag- 
gravated by muscular exertion. These effects have 
generally appeared to be proportioned to the quan- 
tity of venous blood admitted into the aortic system.! 
When these appearances take place immediately 
after birth, it is probable that they depend entirely 
upon malformation of the heart or great vessels ; but 
when they commence at a subsequent period, tliey are 

*■ The student will derive much infoi'mation respecting the pub- 
lications on this subject, prior to 1804, from Dr. Bostock's Essay 
on Respiration — Since the publication of that ess.iy several inte- 
resting papers on respiration have appeared, viz. Two memoirs 
by the late Abbe Spalanzani ; — " An Inquiry into the Changes in- 
duced on Atmospheric Air by the Germination of Seeds, &c."by 
Ellis ; — two very important communications by Messrs. Allen and 
Pepys in the Transactions of the Royal Society of London for 1808 
and 1809 ; — and " Further Inquiries into the changes induced on 
Atmospheric Air." Also by Ellis. 

f Cases of this kind are related in several of the periodical pub- 
lications on medical subjects. Two of them were described by the 
late Dr. William Hunter in the sixth volume of Medical Observa- 
tions and Inquiries, by a Society of Physicians in London ; one 
(quoted by Dr. Goodwyn) is in the Observationes Anatomies of 
Sandifort ; and another, by Dr J S. Dorsey, has lately been pub- 
lished in the first number of the New England Journal of Medicine 
and Surgery. 



Cases of Malformation. 73 

commonly the effect of a diseased alteration in the 
lungs. Thej sometimes occur near the termination of 
fatal cases of pneumonia or catarrh ; but a different 
cause, which has not latterly been suspected, appears 
to have produced them in the following case related 
by Dr. Marcet, in the first volume of the Edinburgh 
Medical and Physical Journal. 

The blue colour occurred in a young woman, twen- 
ty-one years of age, in whom it had never been ob- 
served before.— -It came on during an affection of the 
breast, and was attended with great prostration of 
strength and difficulty of breathing ; as well as cough, 
cedema of the hands and feet, and several other symp- 
toms. About seven weeks after the commencement 
of these symptoms she died; when it was ascertained 
by dissection, that there was no unnatural communica- 
tion whatever between the cavities of the heart, and that 
its valves were all in a perfett and natural state. The 
lunjrs were free from tubercles, or any other appear- 
ance of (lisease. Their substance seemed more com- 
pact than usual, especially the left lung, although it 
did not sink in water ; but they adhered every where 
to the inner surface of the thorax, to the diaphragm, 
and to the pleura covering the pericardium,. — This case 
is the more remarkable, because numberless instances 
have occurred in which very large portions of the ex- 
ternal surface of the lungs have been found upon dis- 
section to adhere to the internal surface of the thorax 
without the occurrence of such symptoms during life. 



It may be inferred, from a statement published bv M. 
Dupuytren in a late volume of the Proceedings of the 
National Institute of France, that the oxygenation or 
decarbonation of the blood is much affected, in respi- 
ration, by an influence exercised by the nerves which 
are appropriated to the lungs. From his account it 
appears, that although the complete division of the 
eighth pair of nerves produces death after some time; 
yet, in the horse whose nerves are thus divided, life 
continues, and respiration goes on, from half an hour 
to ten hours ; but nis arterial blood is in a state of 
great disoxygenation or carbonation, durin^i this time. 
This fact is more remarkable, because venous blood. 

Vol. 1L lO 



74 Effects of Venous Blood on the Heart. 

contained in a bladder exposed to the open air, will 
become oxygenated or decarbonated. 

It is also asserted in another Memoir, read to the 
National Institute by Dr. J. M. Provencal, that ani- 
mals in whom the eighth pair of nerves has been divi- 
ded, do not consume so much oxygen, or produce so 
much carbonic acid, by a considerable degree, as they 
did before the division of these nerves; and that their 
temperature is considerably reduced.* 



The fact, that venous blood occasions death, when it is 
admitted inlo the left ventricle of the heart, and the 
aorta, is truly important. Dr. Goodwin explained it by 
suggesting that this blood was not sufficiently stimulat- 
ing to produce the necessary excitement of the heart ; 
but on this occasion one of his friends proposed to him. 
the following question : Why does venous blood affect 
the left side of the heart in this injurious manner, 
Avhen it appears to exert no noxious effects whatever 
on the right side of that organ ? His reply may be seen 
in a note at the 82d page of his Essay, in the first edi- 
tion. Bichat has ofiered a solution which completely 
resolves this difficulty, viz. " The effect of venous 
blood upon the heart is produced by the presence of 
this blood in the proper, or coronary, arteries of that 
organ, and not in its great cavities." For the anima- 
tion of the heart, like that of the other parts of the 
body, depends upon the state of the blood in the ar- 
teries which penetrate its texture.t And while the 
heart acts, the blood of the coronary arteries will be 
the same with that of the left ventricle. See Bichat's 
Researches, P. II, art. 6, § 2. 

The French Anatomists appear to entertain some pecu- 
liar opinions respecting the course of the blood in the 
foetus, which have a particular relation to the subject 
last mentioned. Winslow, who paid great attention to 
the valve of Eustachius in the right auricle of the 
heart, was of opinion, that this valve was calculated 

* These Memoirs are republished in the Eclectic Repertory 
of Philadelphia for April and October 1811. 

t It is probable that the contents of the great cavities of the 
heart have no more effect upon its animation than the contents 
of the stomach and bowels have upon the animation of those 
organs. 



Sentiments of Sabatiery ^^c. 75 

for some important purpose in the fetal economy. ■■ 
Although his hypothesis respecting its particular use 
has not been retained by his countrymen, many of 
them have adopted his general sentiment; and among 
others Sabatier. That learned anatomist believed that 
this valve, in the fcetal state, serves io direct the blood 
of the inferior cava, after its arrival in the right auricle, 
through the foramen ovale into the left auricle; ivhile 
the blood of the upper cava passes directly into the right 
ventricle. His opinion seems to be supported to a cer- 
tain degree. 

1. By the direction in which the two columns of 
blood enter the auricle from the two vense cavee. 

2. By the position of the Eustachian valve. 

3. By the foramen ovale, when its valve is complete ; 
as the passage through it, from the right to the left, is 
at that time oblique, and from below upwards. 

The theory of Sabatier appears to be this : The um- 
bilical vein brings from the placenta blood which has a 
quality essential to the animation of the foetus. If 
there were no particular provision to the contrary, a 
large portion of this blood, after passing from the um- 
bilical vein by the inferior cava into the right auricle 
of the heart, would proceed by the right ventricle, 
through the pulmonary artery and arterial canal, into 
the aorta, below the origins of the carotid and subcla- 
vian arteries; and consequently none of it would pass to 
the head and upper extremities, but a considerable part 
would return again by the umbilical arteries to the pla- 
centa,without circulatingthrough the body: while on the 
other hand, the blood which passed by the carotid and 
subclavian arteries to the head and upper extremities, 
returning from them to the heart by the superior cava, 
might pass from the right auricle to the left auricle 
and ventricle a'nd the aorta, and so to the head and 
upper extremities again, without passing througli the 
placenta. But by means of this valve, the blood of 
the lower cava, and of course of the umbilical vein, 
is directed to the left auricle and ventricle and the 
aorta, by which a considerable portion of it will ne- 
cessarily pass to the head and upper extremities : 
while the blood which returns from these parts by the 
superior cava, must consequently pass from the right 

See Memoirs of the Academy nf Scicnres for 1717 and XTQ^. 



76 Sentiments of Sabatie)\ 6j-c. 

auricle into the right ventricle and pulmonary artery ; 
from whence a large portion of it will proceed through 
the arterial canal into the aorta beyond the carotids 
and suhclavians, and of this portion a considerable 
part will go to the placenta by the umbilical arteries. 
Sabatier compares the course of the blood in the fcetus 
to the course of a fluid in a tube which has the forn\> 
of the numeral character 8.* — If this doctrine be true, 
the progress of the blood in the fcetus and placenta 
is very analogous to that of the double circulation of 
the adult ; the character 8 answering equally well in 
the description of either subject. 

According to Sabatier, the blood of the placenta 
takes this peculiar course through the heart, in order 
that some of it may be carried to the head and upper 
extremities. But an additional reason may be sug- 
gested, which appears to be of great importance ; viz. 
the supplying of the coronary or proper vessels of the 
heart with some of the same blood. 

The heart of the adult, as has been before stated, 
cannot act without its proper or coronary arteries are 
supplied with arterial blood. The heart of the fcetus 
performs a more extensive circulation than that of the 
adult, and therefore is probably in greater need of 
such blood. ^Vii unless the blood of the placenta pas- 
ses through the foramen ovale into the left auricle and 
ventricle, and so to the aorta, it cannot enter the corona- 
ry arteries which originate at the commencement of the 
aorta; for the blood which flows from the right side 
of the heart through the arterial canal, passes into 
the aorta at so great a distance from the orifices of 
the coronary arteries, that it certainly cannot enter 
them. 

The whole of this doctrine seems to be supported 
by a fact, very familiar to accoucheurs, viz. the occur- 
rence of death in the fcetus whenever the circulation 
through the umbilical cord is suspended during fifteen 
or twenty minutes : for as the placenta imparts to the 
fcetal blood a quality essential to life, some arrange- 
ment seems necessary to provide for the equal distri- 
bution of the blood which comes from this organ, and 



* See Sabatier's Paper on this subject in the Memoirs of the 
Academy of Sciences, for 1774. 



Unusual Cases of Malformation, 71 

especially for carrying the requisite proportion of it 
to the substance of the heart. 



Life has existed for some time with a structure very 
different indeed from that which is natural. In the 
series of elegant engravings relating to morbid ana- 
tomy, published by Dr. Baillie, is the representation, 
of a heart, in which the vense cavfe opened into the right 
auricle, and the pulmonary veins into the left auricle, 
in the usual manner ; but the aorta arose entirely from 
the right ventricle, and the pulmonary artery as com- 
pletely from the left. The canalis arteriosus, howev- 
er, passed from the pulmonary artery to the aorta, and 
the foramen ovale existed. In this case it is evident 
that the pulmonary artery must have carried back to 
the lungs the arterial blood which came from them by 
the pulmonary veins, with a small quantity of venous 
blood that passed into the left auricle through the 
foramen ovale; and that the aorta must have returned, 
to the body, the venous blood which just before had. 
been brought from it by the venee cav«e, with a small 
addition of arterial blood that passed through the 
ductus arteriosus. Yet, with this structure, the child 
lived two months after its birth. 

A case, which had a strong resemblance to the fore- 
going, occurred lately in Philadelphia, and was exam- 
ined by the author of this work. The vense cavse 
terminated regularly in the right auricle, and the pul- 
monary veins in the same regular manner in the left ; 
but the pulmonary artery arose from the left ventri- 
cle, and the aorta from the right. TTiere was no com- 
munication between these vessels by a canalis arterio- 
sus ; but a large opening existed in the septum be- 
tween the auricles. 

It is very evident, that in this case also the pulmo- 
nary artery must have returned to the lungs the arte- 
rial blood as it came from them, and the aorta must 
have canied back to the general system the venous 
blood brought to the heart by the cavpe ; excepting 
only those portions of the arterial and venous blood 
which must have flowed reciprocally from one auricle 
into the other, and thuschanged their respective situa- 
tions. 



78 Fo7'amen Ovale, 

The subject was about two years and a half old. 
The heart was nearly double the natural size, and the 
foramen, or opening in the septum between the auri- 
cles, was eight or nine lines in diameter. The pul- 
monary artery was larger in proportion than the aorta 
or the heart. 

With this organization the child lived to the age 
above specified. His countenance was generally rather 
livid ; and this colour was always much increased by 
the least irregularity of respiration. His nails were 
alivays livid. He sometimes appeared placid, but 
more frequently in distress. He never walked, and 
seldom, if ever, stood on his feet. When sitting on 
the floor, he would sometimes push himself about the 
room ; but this muscular exertion always greatly af- 
fected his respiration. He attained the size common 
to children of his age, and had generally a great ap- 
petite. For some weeks before death his legs and feet 
were swelled. 

It is probable that the protraction of life depended 
upon the mixture of the blood in the two auricles ; and 
that they really were to be considered as one cavity, 
in this case. 



There seems reason to believe, that in adults of the com- 
mon structure, there is no passage of blood from one 
auricle to the other, when the foramen ovale has re- 
mained open ; because in several persons in whom it 
was found by dissection to have remained open, there 
were no appearances during life that indicated the 
presence of disoxygenated blood in the aortic system. 
It is probable, that the small size of the foramen ovale, 
the valvular structure which generally exists there, 
and the complete occupation of the left auricle by the 
blood flowing from the pulmonary veins, prevent the 
passage of blood from the right auricle to the left, in 
such persons; whereas, in the case in question, the 
opening between the auricles was very large indeed, 
and there was no appearance of a valve about it. 



Although it be admitted, that in adults with the fo- 
•ramen ovale pervious, there is no transmission of 



Pn the Sou7'ce of the 3Ioiion of the Heart. 76 

folood froiii the right to the left auricle ; there is every 
reason to believe that this fransmission goes on steadi- 
ly in the fetus. To the arguments, derived from the 
structure and the nature of the case, it may be added, 
that the pulmonary veins, in the fcetal state, carry to 
the left auricle a quantity of blood, not sufficient to 
fill it ; while the venee cavse carry to the right auricle 
not only the whole blood of the body, but of the um- 
bilical cord and placenta : some of which must flow 
into the unfilled left auricle, when the right auricle 
becomes fully distended. 



The question how far the functions of the heart and 
lungs are dependent upon the brain is very important, 
and has often been agitated with great zeal. In fa- 
vour of the opinion that the motions of the heart are 
independent of the brain, may be stated the numerous 
cases in which the brain has been deficient in children, 
who have notwithstanding lived the full period ofutero 
gestation, and even a short time after birth, and have 
arrived at their full size, with every appearance of 
perfect vigour and action in the heart. In support of 
the doctrine, that the action of the heart is immediate- 
ly dependent upon the brain, it may be observed, that 
no organ of the body appears to be so much influenced 
by passions and other mental affections as the heart. 
These contradictory facts have occasioned this ques- 
tion to be considered as undecided, if not incapable of 
solution ; although Cruikshank and Bichat* have sta- 
ted circumstances very favourable to the opinion that 
the motions of the heart are independent of the brain. 



This question seems now to be settled by the expe- 
riments of Dr. Legallois, a physician of Paris, which 

* See Cruikshank's Experiments on the Nerves and Spinal Mar- 
row of living animals ; London Philosophical Transactions for 
1795. The eighth experiment has a particular relation to this 
subject. 

Bichat's Researches, part 2, article 9. 

The Abbe Fontana has considered this subject in his Treatise 
on the Venom of the Viper, vol. ii. page 194, English translation ; 
and also in some of his other works. 



80 Humboldt and others on Legallois' Paper. 

prove, that in animals who have suffered decapitation, 
the action of the heart does not cease as an immediate 
consequence of the removal of the head ; but its ces- 
sation is an indirect effect, induced by the suspension 
of respiration. That respiration is immediately af- 
fected by decapitation, and depends upon the influ- 
ence of the brain transmitted through the eighth pair 
of nerves. That the action of the heart will continue 
a long time afterdecapitation, if inflation of the lungs, 
or artificial respiration, be performed ; but, on the 
contrary, if the spinal marrow be destroyed, the ac- 
tion of the heart ceases irrecoverably. 

The inference from these experiments seems very 
conclusive, that the Spinal Marrow, and not the 
brain, is the source of the motions of the heart. 

It appears also by some of the experiments, that 
the power of motion in the trunk of the body is deriv- 
ed from the spinal marrow ; and that when this organ 
is partially destroyed, the parts which receive nerves 
from the destroyed portion soon cease to live. By 
particular management of the spinal marrow, one 
part of the body can be preserved alive for some time 
after the other parts are dead. 
These experiments of Dr. Legallois commenced in 1806 
or 1807, and were communicated to the Imperial 
Institute of France in 1811. The committee of that 
body to whom they were referred, viz. Messrs. 
Humboldt, Halle and Percy, reported that the expe- 
riments had been repeated before them, at three dif- 
ferent meetings of several hours each ; and that to 
allow themselves sufficient time for reflection, they 
suffered an interval of a week to take place be- 
tween the meetings. The committee believe these 
experiments to have proved, 

1st. That the principle upon which all the move- 
ments of inspiration depend, has its seat about that 
part of the medulla oblongata from which the nerves 
of the eighth pair arise. 

2d. That the principle which animates each part of 
the trunk of the body is seated in that portion of the 
spinal marrow from which the nerves of the oart arise. 

3d. That the source of the life and strength of the 
heart is also in th'e spinal marrow ; not in any distinct 
portion, but in the whole of it. 



Brodie on the Source of the Motion of the Heart. 81 

4th. That the great sympathetic nerve is to be consi- 
dered as originating in the spinal marrow, and that the 
particular character of this nerve is to place each of 
the parts to which it is distributed under the imme- 
diate influence of the whole nervous power. 
The interesting memoir of Dr. Legallois is confirmed 
to a certain degree by a communication of B. C. 
Brodie to the Royal Society of London in 1810, in 
which are detailed many very interesting experi- 
ments which induced the author to conclude, — 

That the influence of the brain is not directly ne- 
cessary to the action of the heart; and 

That when the brain is injured or removed, the ac- 
tion of the heart ceases, only because respiration is un- 
der its influence ; and if under these circumstances 
respiration is artificially produt:ed, the circulation 
will still continue. 
These various experiments apply particularly to the 
cases in which the brain is deficient. The effects of 
mental agitations on the heart are likewise reconcile- 
able to the theory which arises out of them. But they 
throw no light on the question why the motions of 
the heart are so perfectly free from the influence of 
the will: and although they seem to prove incon- 
testably that the motion of the heart is independent 
of the brain, it ought to be remembered that in cer- 
tain diseased states of the brain, where that organ ap- 
pears to be compressed, the action of the heart is often 
very irregular, and its contractions less frequent than 
usual. 



Vol. II. 11 



SYSTEM OF ANATOMY, 
PART VIII. 



OF THE ABDOMEN. 

The lowermost of the two great cavities of the 
trunk of the body is called Abdomen. The pelvis 
may be considered as a chamber of this cavity, al- 
though its structure is very different. 

CHAPTER I. 

A GENERAL VIEW OF THE ABDOMEN AND PELVIS AND 
THEIR CONTENTS, WITH AN ACCOUNT OF THE PE- 
RITONEUM. 

SECTION I. 

Of the Abdomen. 

This great cavity occupies more than half of the 
space inclosed by the ribs, and all the interior of the 
trunk of the body below the thorax. 

It is formed by the diaphragm, supported by the 
lower ribs ; by a portion of the spine ; by the various 
muscles which occur between the lower margin of 
the thorax and the upper margin of the ossa innomi- 
nata; and by the ossa innominata, which contribute, 
for the purpose, the costse of the ossa ilia, as well as 
the pelvis. 



Construction of the Abdomen. 83 

The general figure of this cavity partakes of the 
figure of the lower part of the trunk of the body ; 
with these exceptions, that the diaphragm makes it 
arched or vaulted above, that the spine and psoaoe 
muscles, &c. are rather prominent on the posterior 
surface, and that the lower part corresponds with the 
costai of the ossa ilia and with the pelvis. 

To acquire a precise idea of this cavity, it is ne- 
cessary first to study the bones concerned in its 
structure, in their natural situation in the skeleton ; 
and then the muscles, which form so large a part 
of it. 

The arrangement of the tendons of some of these 
muscles, with a view to complete the cavity, is par- 
ticularly interesting ; as that of the external oblique 
where it forms the crural arch.* The ligaments of 
the pelvis and the levatores ani muscles, as they also 
contribute to the formation of the cavity, and have 
an influence upon its figure, should likewise be at- 
tended to. 

In the walls of the cavity, thus constructed, there 
are many foramina by which the viscera and other 
contained parts communicate externally ; but few of 
them pass directly into the cavity; for like the thorax, 
there are no vacuities in it exterior to the contained 
organs. 

Three of these foramina are in the diaphragm. 
One for the transmission of the aorta, another for the 
vena cava, and a third for the oesophagus. Below, 
there is an aperture at each of the crural arches, for 
the transmission of the great femoral vessels ; in each 
of the ligamentous membranes, which close the fora- 
men thyioideum, for the obturator vessels and nerve ; 
and at the sacro sciatic notches, for nerves and blood 
vessels. 

* See the account of this tendon, vol. i. in the description of tlie 
" Obhquus Uecendens Externus." 



84 Construction of the Mdomen, 

There are also two apertures at the bottom of the 
pelvis, for the orifice of the rectum and of the urethra. 
In the tendons of the external oblique muscles are 
two orifices, covered by the integuments, for the sper- 
matic cords ; and, in the foetal state, one for the um- 
bilical cord. 

The apertures in the tendons, and under their 
edges, for the transmission of the spermatic cords, 
and the blood vessels, &c. are not to be considered 
as simple perforations made abruptly ; but the edges 
of these foramina are formed by tendinous mem- 
branes turned inwards and continued so as to com- 
pose a cylindrical tube, which becomes gradually so 
thin that it cannot be readily distinguished from the 
cellular membrane with which it is connected.* The 
blood vessels, &c. pass along this tube before they 
go through the apertures. ^ 

It is evident from the construction of this cavity 
that it is essentially different from the thorax. It 
has no power of spontaneous dilatation whatever : it 
yields passively to the distension of the stomach and 
intestines, during deglutition, and when air is extri- 
cated from the aliment, &c.; but it is particularly 
calculated for compressing its contents by the con- 
traction of the muscles which compose it. The di- 
minution of its capacity, which is thus effected, not 
only takes place to a great degree, but occasionally 
with great force. The diaphragm and the abdomi- 
nal muscles may be considered in some measure as 
antagonists of each other. When the diaphragm 
descends, if the abdominal muscles are passive, they 
are distended by the contents of the abdomen, which 
are forcibly pressed from above ; but if the abdomi- 
nal muscles act at the same time, an effort to dimi- 

* The student of anatomy, when engaged with this subject, will 
be gratified by the examination of Mi'. Astley Cooper's plates re- 
latinar to herniac. 



Contents of the Abdomen. 85 

iiish the cavity in every direction takes place, and 
the contained parts are compressed with more or less 
force according to the exertion made. This will be 
very evident upon examining the situation of the 
diaphragm and of the abdominal muscles. When 
their force is considered it will also be very obvious 
that the various outlets of the cavity are constructed 
most advantageously : otherwise hernia or protrusion 
of its contents would be a daily occurrence. 

The abdomen contains, 1st. The Stomach and the 
ivhole Intestinal Tube, consisting of the small and 
the great intestines. 

2d. The Assisting Chylopoietic Viscera, — the Li- 
ver, the Pancreas and the Spleen. 

3. The Urinary Organs^ — the Kidneys, the Ure- 
ters, and the Bladder. To which should be added 
the Glandulse Renales. 

4th. The Organs of Generation in part : those of 
the female sex being almost wholly included in the 
pelvis ; and those of the male being situated partly 
within and partly without it. 

5th. The Peritoneum and its various processes. 
The Mesentery, Omentum, &c. 

6th. A portion of the Aorta^and almost the ivhole 
of the Inferior Cava, and their great ramifications ; 
with sucli of their branches as are appropriated to 
the Viscera of the Abdomen and Pelvis. 

7th. Those portions of the Par Vagum and Inter- 
costal JVerves which are appropriated to the cavity ; 
and portions of some of the nerves destined to the 
lower extremities. 

8th. The lower part of the Thoracic Duct, or th« 
Great Trunk of the Absorbent System, with the 
large branches that compose it, and the glands con- 
nected with them ; and also those absorbent vessels 
called Lacteals, and their glands. 

As the cavity of the abdomen has no natural divi- 



86 Regions of the Abdomen. 

sions, anatomists have divided it by imaginary lines 
inio various regions, with a view to precision in their 
accounts of the situation of the dilferent contained 
parts. Thus, 

They have, very generally, agreed to apply two 
transverse lines to form three great divisions ; viz. 
the Upper, Middle and Lower: and they have also 
agreed that each of these divisions shall be subdi- 
vided into three regions. 

The three regions of the uppermost division are 
defined with some precision. Those on each side, 
which are called the Right and Left Hypochondriac 
i^egions, occupy the spaces immediately within the 
lower ribs and their cartilages; while the middle 
space, included within the margins of these carti- 
lages, and a line drawn from the lower edge of the 
thorax on one side to that on the other, is denomi- 
nated the Epigastric region. 

The boundaries of the regions below are less pre- 
cisely defined. 

Many anatomists have fixed the two transverse 
lines above mentioned at an arbitrary distance above 
and below the umbilicus : some choosing for this 
purpose two inches, and others a hand's breadth. 
As these distances will occupy different proportions 
of the cavity in persons of different stature, other 
anatomists, with a view to avoid this inconvenience, 
have proposed to connect these lines with certain 
fixed points of the skeleton. 

It is of importance that the boundaries of these 
regions should be fixed, and therefore the proposi- 
tion of Sabatier may be adopted ; viz. To draw the 
upper transverse line from the most inferior part of 
the lower margin of the thorax, on one side, to the 
corresponding part on the opposite side; and the 
lower transverse line from the uppermost part of the 



Regions of the Abdomen* 87 

spine of one ilium to the same part of the other. 
These lines will mark the tiiree great divisions. If 
then two parallel lines are drawn directly upwards^ 
one from each of the superior anterior spinous pro- 
cesses of the ilium until it touches the lower margin 
of the thorax, they will divide each of the two lower 
divisions of the abdomen into three regions. The 
centre of the middle division is the umbilical, and 
on each side of it is the right and left lumbar region. 
The middle of the lower division is the hypogastric ; 
and on each side of it the right and left iliac region. 

It is true, that the three middle regions of the ab- 
domen will be made very small by the vicinity of 
the transverse lines to each other ; but the advan- 
tages derived from a principle which is similar in 
its application to all subjects fully compensates for 
this inconvenience. 

There are therefore nine of these regions : viz. The 
Epigastric and the two Hypochondriac : the Umbi- 
lical, and the two Lumbar : the Hypogastric, and 
the two Iliac regions.* And it should be added, 
that the space immediately around the end of the 
sternum is sometimes called the Scrohiculus Cordis ; 
and the space immediately within the os pubis, the 
Regio Pubis. 

These different regions are generally occupied in 
the following manner. The liver fills nearly the 
whole of the right hypochondriac region, and ex- 
tends through the upper part of the epigastric region 
into the left hypochondriac. The stomach occupies 
the principal part of the epigastric region, and a 
considerable portion of the left hypochondriac. The 
spleen is also situated in the left hypochondriac re- 

* It is to be observed that the lateral regions of the middle and 
lower divisions of the abdomen are named differently by different 
writers. 



88 Situation of the Viscera, ^c. in the 

giou. That portion of the intestinal tube, which is 
composed of small intestines, is generally found in 
the umbilical, the hypogastric, and the iliac regions ; 
and when the bladder is empty, in the pelvis. But 
the duodenum, or first of the small intestines, which 
proceeds immediately from the stomach, is situated 
in the epigastric and umbilical regions. The great 
intestine commences in or near the right iliac region, 
and ascends through the right lumbar to the right 
hypochondriac region. It then crosses the abdomen, 
passing through the lower part of the epigastric^ or 
upper part of the umbilical to the left lumbar region ; 
from this it continues into the left iliac region, and 
curves in such a manner that it finally arrives at the 
middle of the upper part of the os sacrum, when it 
descends into the pelvis, and, partaking of the cur- 
vature of the last mentioned bone, continues to the 
termination of the os coccygis. 

In the back part of the epigastric region, and very 
low down in it, is situated the pancreas. The kid- 
neys lie in the most posterior parts of the lumbar 
regions, and from each of them is continued a tube 
or duct, called Ureter, that passes into the pelvis to 
convey the urine to the bladder. This viscus, in 
males, is in contact with the last portion of the great 
intestine called the Rectum, and with it occupies 
almost all of the cavity of the pelvis ; while in fe- 
males, the uterus and its appendages are situated 
between this intestine and the bladder. 

In the posterior part of the abdomen, in contact 
with the spine, is the aorta. This great blood ves- 
sel passes from the thorax between the crura of the 
diaphragm, and continues down the spine until it 
approaches towards the pelvis, when it divides into 
two great branches called the Iliac Arteries, Each 
of these great branches divides again, on the side 



Cavity of the Mdomen. 89 

of the pelvis, into two; viz. the External Iliac, 
which passes under the crural arch to the thigh, 
and the Internal Iliac, or Hypogastric, which de- 
scends into the cavity of the pelvis. 

Soon after the arrival of the aorta in the abdomen 
it gives oif two large branches. The first, which is 
called the Cceliac, is distributed to the liver, th' sto- 
mach, and the spleen : the second, called the Supe- 
rior Mesente?'ic^ is spent upon the intestines. Lower 
down, in the abdomen, it also sends off a small 
branch for the intestines, called the Inferior Mesen- 
teric. Besides these vessels for the chylopoietic 
viscera, the aorta sends off a large branch, called 
Emulgents to each kidney. 

The inferior, or ascending vena cava, is situated 
on the right of the aorta, in front of the spine. ' It is 
formed below by the union of the iliac veins, and in 
its progress upwards it receives the eaiulgent veins, 
which correspond to the arteries of the kidneys ; but 
it receives in its course no veins which correspond 
directly with the coeliac and mesenteric arteries. 
The smaller veins, that answer to the branches of 
these arteries, unite and form one large vein, which 
goes to the liver, and is called (from the part of that 
viscus at which it enters) Vena Portarum. From 
the liver three large veins pass into the vena cava, 
and deposit tliere the blood of the vena portarum, 
after it has furnished inaterials for the secretion of 
bile. The vena cava, in its passage upwards, is in 
close contact with the posterior thick edge of the 
liver: it often passes along a deep groove in this 
edge, and sometimes it is completely surrounded by 
the liver in its coarse. The veins of the liver enter 
the vena cava at this place, and of course they are 
not to be seen without dissection. Immediately af- 
ter leaving the liver the vena cava passes through an 

Vol. II. 12 



90 The Peritoneum. 

aperture in the tendinous centre of the diaphragm 
to unite itself to the right auricle of the heart. 

SECTION' II. 

Of the Peritoneum. 

The abdomen, thus constructed and occupied, is 
lined by a thin firm membrane called Peritoneum, 
which is extremely smooth on its internal surface, 
and is intimately connected with the cellular sub- 
stance exterior to it. This membrane adheres close- 
ly to the anterior, lateral, and superior portions of 
the surface of the abdomen; and is extended from the 
posterior surfiice so as to cover, more or less com- 
pletely, the viscera of the cavity. Those viscera 
which are in close contact with the posterior surface 
of the abdomen, as some portions of the large intes- 
tine, are covered only on their anterior surfaces, and 
are fixed in their precise situations by the perito- 
neum ; which extends from them to the contiguous 
surface of the cavity, and adheres where it is in con- 
tact, so as to produce this effect. 

Other viscera, which are not in close contact, but 
moveable to a distance from the posterior surface of 
the abdomen, are covered by this membrane, which 
is extended to them from the surface ; and this ex- 
tended portion forms an important part of the con- 
nexion between the viscus and the cavity in which it 
lies. This connecting part is called Mesentery , 
when it thus passes to the small intestines ; Mesoco- 
lon, when it goes to the colon, one of the larger in- 
testines ; and Ligament, when it passes to some of 
the other viscera. 

The peritoneum is a complete but empty sac, 
which is fixed in the abdomen anterior to the viscera. 
The anterior portion of this sac forms the lining to 
the anterior and lateral parts of the surface of the 



The Peritoneum. 91 

abdomen : the posterior portion covers the viscera, 
and forms the mesentery, mesocolon, and ligaments 
above described. 

It necessarily follows that the mesentery and the 
other similar processes are mere plaits or folds of the 
sac, vt'hich invests the viscera ; and that they must 
consist of two laminse : and as the blood vessels, 
nerves, and absorbents, are all posterior to the peri- 
toneum, they naturally pass between these laminae 
of the mesentery. 

Some of the viscera are much more corajj-letely in- 
vested witli the peritoneum than others. The sto- 
mach, liver, and spleen, are almost completely 
surrounded by it ; and it is said to form a coat for 
each of these viscera. That portion of the smaller 
intestinal tube, which is called JRJunum and ileum, 
and the transverse portion of the large intestine, call- 
ed the arch of the colon, are invested by it in the 
same way. But a considerable portion of the duo- 
denum and the pancreas is behind it. The lateral 
portions of the colon are in close contact with the 
posterior surface of the abdomen, and the peritone- 
um only covers that portion of their surfaces which 
looks anteriorly towards the cavity of the abdomen, 
and is not in contact with its posterior surface. 

The urinary organs are not much connected witli 
the peritoneum. The kidneys appear exterior to it, 
and behind it : the bladder of urine is below it, and 
has but a partial covering from it, on its upper 
portion. 

The peritoneum, which covers the stomach, is ex- 
tended from the great curvature of that organ so as 
to form a large membrane, which descends like an 
apron before the intestines. This process of perito- 
neum is composed of two laminae, so thin and deli- 
cate as to resemble cellular membrane, which, after 
extending downwards to the lower part of the abdo 



93 The Peritoneum. 

men, are turned backwards and upwards, and pro- 
ceed in that direction until they arrive at he colon, 
"Which they inclose, and then continue to the back of 
the abdomen, forming the mesocolon. The part of 
this process which is between the stomach and the 
colon, is called Epiploon or Omentum. 

This extension of a membrane, from the surface 
of a cavity, which it lines to the external surface of 
a viscus in that cavity, is called, by some anatomists, 
'' reflection ;" and the technical term reflected mem- 
brane is therefore applied to a membrane distributed 
like the peritoneum. 

It must be evident that this distribution of the pe- 
ritoneum is very complex, and that it is not easy to 
form an accurate conception of it from description, 
but it can be readily understood by demonstration ; 
therefore no further account of its arransjement will 
now be attempted, but each of its processes will be 
considered with the organs to which they are parti- 
cularly subservient. 

That portion of the peritoneum which lines the 
abdomen and covers the viscera is thin and delicate, 
but very firm. It yields to distension, as in preg- 
nancy, ascites, &c. and again recovers its dimen- 
sions. It was formerly thought to be composed of two 
laminae, but this cannot be proved. The internal 
surface of this membrane is very smooth, and highly 
polished ; and from it exudes a liquor which is well 
calculated for lubrication, and barely suificient to 
keep the surface moist during health ; but sometimes 
it is very abundant, and occasions the aforesaid dis- 
ease — ascites. This fluid appears to exude from 
the surface of the peritoneum when it is compressed 
in a living animal, or in one recently dead. It is 
probably eifused from the extremities of arteries, for 
an effusion takes place when water is injected into 
these vessels. 



The Peritoneum. 98 

The peritoneum abounds with absorbent vessels, 
and therefore possesses the power of absorption to a 
great degree. This power may be inferred, not 
only from the spontaneous removal of the fluid of 
ascites, but if milk and water be introduced into the 
abdomen of a living animal, through a puncture, it 
■will also disappear. 

The blood vessels of the peritoneum are derived 
fVom those which supply the neiglibouring parts. 
Nerves have not yet been traced into it, and it has 
little or no sensibility. 

This membrane supports the viscera of the abdo- 
men in their proper situations ; and also forms a sur- 
face for them, and for the cavity which contains 
them, so smooth and lubricated, that no injury can 
arise from their friction. 

The cellular substance, by which the peritoneum 
is connected to the contiguous parts, is very different 
in different places. It is very short indeed between 
this membrane and the stomach and intestines, and 
also between it and the tendinous centre of the dia- 
phragm. Between the peritoneum and the muscles 
generally, it is much longer. When it covers the 
kidneys and the psoas muscles it is very lax and 
yielding. About the kidneys a large quantity of 
adeps very commonly collects in it. On the psoas 
muscle it yields with but little resistance to the pas- 
sage of pus, or any other effused fluid, as in the 
case of the psoas abscess. 



CHAPTSU II. 

OF THE (ESOPHAGUS, THE STOMACH, AND THE INTESTINES. 
SECTION I. 

Of the (Esophagus. 

The (Esophagus is a muscular tube vVhich passes 
from tlie pharynx to the stomach, and is so intimately 
connected with the stomach, that it will be advan- 
tageous to the student to attend to its structure im- 
mediately before he engages in the examination of 
that important organ. 

The pharynx has been lately described* as com- 
posed of a varied stratum of muscular fibres, lined 
by a membrane which is continued from the internal 
surface of the nose and mouth. From the pharynx 
the oesophagus passes downwards between the tra- 
chea and the vertebrae. After the bifurcation of the 
trachea, it proceeds in contact with the spine, be- 
tween the laminae of the mediastinum, to the dia- 
phragm, which it passes through, and then termi- 
nates in the stomach. 

The oesophagus is a flexible tube, which, when 
distended, is nearly cylindrical. It consists of a 
muscular coat externally, and an internal tunic evi- 
dently continued from that of the pharynx. These 
coats are connected by a cellular substance called 
the JVervous Coat, which is remarkably loose, and 
allows them to move considerably upon each other. 
The muscular coat which is very distinguishable 
from that of the pharynx, consists of two substantial 
strata of fibres ; the exterior of which is nearly lon- 

* See page 3T. 



The (Esophagus. 95 

gitiidinal in its direction, and the interior circular or 
transverse. 

The internal coat of the oesophagus, resemhling 
that of the fauces, is soft and spongy. It is covered 
with a very delicate cuticle, wisich Haller supposed 
to be too tender to confine the matter of variolus 
pustules, as he had never found these extending into 
the oesophagus. It is very vascular, and abounds 
with the orifices of mucous follicles, from which is 
constantly poured out the mucous that is spread over 
this surface. When the oesophagus is not distended, 
many longitudinal plaits are found in this membrane 
by the contraction of the circular or transverse fibres 
exterior to it. These plaits are calculated to admit 
readily of the distention which is requisite in deglu- 
tition. This tunic is continued from the lining mem- 
brane of the pharynx above, and terminates below 
in the villous coat of the stomach ; from whicli, how- 
ever, it is very different. 

The blood vessels of the oesophagus come from 
those which are in the vicinity. The nerves are de- 
rived from the eighth pair. The lymphatic vessels 
are very abundant. 

In the neck, the oesophagus inclines rather to the 
left of the middle line. As it proceeds down the 
back between the laminae of the mediastinum, it pre- 
serves the same course to the fourth dorsal vertebra, 
when it assumes the middle portion and proceeds 
downwards, with the aorta to its left, and the peri- 
cardium before it. About the ninth dorsal vertebra 
it inclines again rather to the left, and somewhat 
forward, to arrive at the aperture in the diaphragm 
through which it passes. 

Throughout this course it is connected by cellular 
membrane to the contiguous parts ; and this investi- 
ture of cellular membrane has been called its Ex- 
ternal Coat- 



96' Form of the Stomach. 

While the oesophagus is in the posterior mediasti- 
num, it is in contact with several small absorbent 
glands, especially when it first assumes a situation 
to the right of the aorta. These glands were for- 
merly believed to be particularly connected with 
this tube, but they are now considered as belonging 
to the absorbent system. They are sometimes greatly 
enlarged. 

SECTION II. 

Of the Stomach. 

This most important organ, which occasionally 
exerts a powerful influence upon every part of the 
body, appears very simple in its structure. 

It is a large sac, which is so thin when much in- 
flated that at first view it seems membranous, but 
upon examination is found to be composed of seve«- 
ral laminae or coats, each of a different structure. It 
is of considerable length, but incurvated. It is much 
larger at one extremity than the other, and changes 
so gradually in this respect, that it would appear 
conical if it were straight. It is not, however, strictly 
conical, unless it is greatly distended ; for when 
moderately distended, a transverse section is rather 
oval than circular. It is therefore considered as hav- 
ing two broad sides or surfaces, and two edges, 
which are the curvatures. It has been compared 
by the anatomists of different nations to the wind 
sac of the musical instrument called the bag-pipe.* 
The orifice in which the oesophagus terminates is at 
a small distance from its largest extremity, and is 
called Cardia. The orifice which communicates 

* The student ought not to attempt to acquire an idea of the 
form of the stomach without ilemonsiratioii. for a view of one 
moment will be more serviceable than a long description. 



fif9 Position of the Stomach. 97 

Avitli the intestines is at the termination of its small 
incurvated extremity, and is called the Pylorus. 

The two ends of the stomach being thus very dif- 
ferent in size, are denominated the great and small 
extremities. The two curved portions of tlie sur- 
face are also calle;! the great and small curvatures. 
The two flat portions of th.e surface, or the broad- 
sides, are called the anterior and posterior surfaces. 

The situation of the stomach in the abdomen is 
nearly transverse : it lies principally in the left hy- 
pochondriac and epigastric regions, immediately be- 
low the liver. The great extremity of the stomach 
is in the left hypochondriac region, and the lesser 
extremity in the epigastric region, under the left 
lobe of the liver. The upper orifice, or Cardia, is 
nearly opposite to the body of the last dorsal verte- 
bra ; and, owing to the curved form of the stomach, 
the other orifice, or Pylorms, is situated at a small 
distance to the right of that bone, and rather lower 
and more forward than the cardia : both orifices be- 
ing in the epigastric region. The position of the 
. stomach is oblique in two respects ; it inclines in a 
small degree from above downwards, from the left 
to the right ; and it also inclines downwards and 
forwards, from behind. Its two orifices are situated 
obliquely with respect to each other ; for, if the 
stomach, when placed with its small curvature up- 
wards, were divided into two equal parts by a verti- 
cal plane passing lengthways through it, they would 
be found on different sides of the plane. 

As the oesophagus terminates in the stomach im- 
mediately after it has passed through an aperture of 
the diaphragm, it is evident that the stomach must 
be somewhat fixed at that place ; but it is more 
moveable at its other orifice ; for the extremity of 
the duodenum, into which it is continued, is move- 
able. 

Vol. TI. 13 



98 External Coat of the Stomach. % 

The stomach is connectocl to the concave surface 
of tlie liver hy the retlexioii or continuation of the 
peritoneum, which forms the lesser omentum. This 
membrane, after extending over each surface of the 
stomach, continues from its great curve in the form 
of the large omentum, and connects it to different 
parts, especially to the colon. There are likewise 
folds of the peritoneum, as it passes from the dia- 
phragm and from the spleen to the stomach, which 
appear like ligaments. 

Notwithstanding these various connexions, the 
stomach undergoes considerable changes in its posi- 
tion. When it is nearly empty, and the intestines 
are in t!ie same situation, its broad surfaces are pre- 
sented forwards and backwards; but when it is dis- 
tended, these surfaces are presented obliquely up- 
wards and downwards, and the great curvature for- 
wards. When its anterior surface is presented up- 
wards, its orifices are considerably influenced in 
their direction, and the oesophagus forms an angle 
with the plane of the stomach. 

The stomach is composed of four dissimilar lami-. 
nse, which may be demonstrated by a simple pro- 
cess of dissection. 

There is iirst a coat or external covering conti- 
nued from the peritoneum : within this, and connect- 
eji to it by delicate cellular substance, is a coat or 
stratum of muscular fibres: contiguous to tliese 
fibres, internally, is a layer of dense cellular sub- 
stance, called a nervous coat; and last is the inter- 
nal coat of the stomach, called villous, or fungous, 
from the structure of its surface. 

The external or first coat of the stomach, as has 
been already stated, is continued from the concave 
surface of the liver to the lesser curve of the sto- 
mach in two delicate laminae, which separate when 
they approach the stomach, and pass down, one on 



Muscular and JVervous Coats of the Stomach. 99 

each side of it, adlieriiig firmly to it in their course : 
at the opposite curve of the stomach they again unite 
to form the great omentum. The stomach is there- 
fore, ch)sely invested by the peritoneum on every 
part of its surface except two strips, one at the lesser 
and the other at the greater curvature. These strips 
or uncovered places are formed by the separation of 
the laminae above mentioned, which includes a trian- 
gular space bounded by the stomach and these two 
lauiinse. In these triangular spaces, at each curva- 
ture of the stomach, are situated the blood vessels 
which run along the stomach in those directions, 
and also the glands which belong to the absorbent 
vessels of this viscus. Tbe peculiar arrangement 
of the laminse at this place is particularly calculated 
to permit the dilatation of the stomach. When it is 
dilated the laminae are in close contact with its sur- 
face, and the blood vessels being in the angle form- 
ed by the adhesion of the two laminse to each other, 
are so likewise : when it contracts, the blood ves- 
sels appear to recede from it, and the laminae are 
then applied to each other. 

Where t!ie peritoneum thus forms a coat to the 
stomach, it is stronger and thicker than it is between 
the liver and stomach. In a recent subject it is 
very smooth and moist, but so thin that the muscu- 
lar fibres, blood vessels, &c. appear through it. If it 
is carefully dissected from the muscular coat, it ap- 
pears somewhat fiocculent on that surface which ad- 
hered to the muscular fibres. It seems to be most 
abundantly furnished with serous vessels ; but it 
has been asserted by Mascagni and Soemmering, 
that a large proportion of its texture consists of ab- 
sorbent vessels. The cellular substance vvhicii con- 
nects this to the muscular coat appears no way dif- 
ferent from ordinary cellular jmerabrane. 

The Muscular Coat of the stomach has been de- 



100 Internal Coat of t lie Stomach. 

scvi!)ed very differently 'by respectable anatomists ; 
some considering it as forming three strata of fibres, 
and otliers but two. If the stomach and a portion 
of tiie (Esophagus attached to it be moderately dis- 
tended with air, and the external coat carefully dis- 
sected away, many longitudinal fibres will appear on 
every part of it, that evidently proceed from the 
oesophagus : these fibres are particularly numerous 
and strong on the lesser curvature of the stomach. — 
Beside the longitudinal fibres there are many that 
have a circular direction, and these are particularly 
numerous towards the small extremity ; but it has 
been doubted whether there are any fibres in the 
muscular coat of the stomach that go directly round 
it. The whole surfiice of the stomach, when the 
peritoneal coat is removed, appears at first view to 
be uniformly covered by muscular fibres ; but upon 
close examination, there are interstices perceived;^ 
vv^hich are occupied with firm cellular membrane. 

In contact with the internal surface of the muscu- 
lar coat is the cellular stratum, which has been 
called the JVei'vous Coat of the stomach. It is dense 
and firm, of a whitish colour, resembling condensed 
cellular membrane. It was considered as different 
from ordinary cellular membrane ; but if air be insi- 
nuated into its texture, by blowing between the mus- 
cular and villous coats, while it connects them to 
each other, it exhibits the proper appearance of cel- 
lular substance. It however adds greatly to the ge- 
neral strength of the stomach, and tiie vessels which 
terminate in the villous coat ramify in it. 

The internal coat of the stomach in the dead sub- 
ject is commonly of a whitish colour, with a tinge of 
red. It is named villous, from its su|)posed resem- 
blance to the surface of velvet. It has also been 
called fungous, because the processes analogous to 
the villi are extremely short; and its surface has a 



Gastric Liquor. 101 

grauulated appearance ; diifering in these respects 
from the internal surface of the intestines. It is con- 
tinued from the lining membrane of the cesophagus, 
but is very different in its structure. Many very 
small vessels seem to enter into its texture, which 
are derived from branches that ramify in the nervous 
coat. It is supposed by several anatomists of the 
highest authority, to have a cuticle or epithelium ; 
and it is said that such a membrane has been sepa- 
rated by disease. It ought however, to be remem- 
bered, that the structure of the villous coat of the 
stomach and intestines, is essentially different from 
the structure of the cuticle. 

The internal coat of the stomach is generally 
found covered, or spread over, with mucous, which 
can be readily scraped off. This mucous is certainly 
effused upon it by secreting organs, and it has been 
supposed that there were small glandular bodies ex- 
terior to the villous coat, which furnished this'secre- 
tion ; but the existence of such bodies is very doubt- 
ful, as many skilful anatomists have not met with 
any appearance that could be taken for glands, ex- 
cept in a very few instances, wliich would not be the 
case if those appearances had been natural. Pores, 
perhaps the orifices of mucous follicles, and also of 
exlialent vessels, are very numerous, but no proj)er 
glandular masses are attached to them. Glands, as 
have been already said, are found in the triangular 
spaces between the laminie of the peritoneum at the 
great and small curvatures of the stomach, but these 
evidently belong to the absorbent system. Besides 
the mucous al>ove mentioned, a large quantity of a 
different liquor, the proper Gastric Juice, or fluid of 
the (itomach, is effused from its surface. It has been 
supposed that this fluid is furnished by the small 
glaiulnlar bodies believed to exist between the coats 
of tliis organ ; but, admitting the existence of these 



103 ' The Pylorus. 

glands, they are not sufficiently numerous to produce 
so aiuch of it as is found, and it is therefore proba- 
ble that this fluid is discharged from the orifices of 
exhalent vessels in the internal surface. 

Much information respecting the gastric liquor 
has been obtained within a few years past by the 
researches of physiologists, and they are generally 
agreed that it is the principal agent in the effects 
produced by the stomach upon alimentary sub- 
stances.* 

As the muscular coat of the stomach frequently 
varies its dimensions, the villous and nervous coats, 
which have no such power of contraction, cannot 
exactly fit it. They therefore generally appear 
larger, and of course are thrown into folds or 
rugae. These folds are commonly in a longitudinal 
direction ; but at the orifices of the stomach they are 
arranged in a radiated manner, and sometimes they 
are observed in a transverse direction. They de- 
pend upon the contraction of the muscular fibres, 
and disappear entirely when the stomach is laid open 
and spread out. 

At the lower orifice is a circular fold, which is 
permanent, and constitutes the valve denominated 



* On this subject the student may consult with advantage, 

M. Reaumur. In the Memoirs of the Academy of Sciences for. 
1752. 

John Hunter. London Philosophical Transactions for 1772; and 
also his observation on the x\nimal Economy, 1786. 

Dr. Edward Stevens. Inaugural Thesis de Alimentorum Con- 
Goctione. Edinburgh, 1777. 

The Abbe Spalanzani. Dissertations relative to Natural His- 
tory, &c. The first volume of the English translation contains the 
author's dissertations on digestion, and also the first paper of 
Mr. Hunter, and the Thesis of Dr. Stevens, as well as an account 
of the experiments of Mr. Gosse of Geneva. 

In addition to these, there are several interesting essays m the 
French, German, and Itali-in languages, a compilation of which is 
to be found in Johnson's " History of the progress and present state 
of Animal Chemistry." See Vol I. page 180. 



Lymphatics and JVerves of the Stomach. 103 

Pylorus. It appears like a circular septum with a 
large foramen in its centre, or like a flat ring. The 
villous and nervous coats of the stomach contribute 
to this, merely by forming the circular fold or ruga ; 
and within this fold is a ring of muscular fibres, evi- 
dently connected with the circular fibres of the mus- 
cular coat of the stomach, the diameter of which at 
this place is not larger than that of an intestine : the 
fibres of this ring seem a part of the muscular coat 
projecting into the cavity of the stomach and duode- 
num. If a portion of the lesser extremity of the sto- 
mach and the adjoining part of the duodenum be 
detached, and laid open by a longitudinal incision^ 
and then spread out upon a board, the internal coat 
can be very easily dissected from the muscular, and 
the pylorus will then appear like a ridge or narrow 
bundle of muscular fibres, which runs across the ex- 
tended muscular membrane. It is evident that when 
the parts are replaced so as to form a cylinder, this 
narrow faciculus will form a ring in it. Thus ar- 
ranged, the circular fibres can readily close the low- 
er orifice of the stomach. 

The pylorus separates the stomach from the in- 
testine duodenum ; and this separation is marked 
exteriorly by a small circular depression, which cor- 
responds exactly with the situation of the pylorus. 

The arteries of the stomach are derived from the 
CoeliaCf the first branch which the aorta sends ofiPto 
the viscera of the abdomen. This great artery, im- 
mediately after it leaves the aorta, is divided into 
three branches, which are distributed to the stomach, 
the liver, and the spleen, and are called the Supe- 
rior Coronary or Gastric, the Hepatic, and the 
tSjjlenic. Beside the first mentioned branch, which 
is distributed principally to the neighbourhood of 
the cardia and to the lesser curvature, tiie stomach 
receives a considerable branch from the hepatic. 



104 The Intestines in general. 

which passes along the right portion of its great cur- 
vature, and has been called the right gastro-epiploic, 
and another from the spleen, which passes along the 
left portion of the great curvature, and has been call- 
ed the left gastro-epiploic. In addition to these 
branches, the splenic artery, before it enters the 
spleen, sends off several small arteries to the great 
extremity of the stomach, which are called vasa 
brevia. 

These vasa brevia generally arise from the main 
trunk of the splenic artery, but sometimes from its 
branches. 

The veins which receive the blood from these 
arteries have similar names, and pursue correspond- 
ing courses backwards ; but they terminate in the 
vena portarum. 

The absorbent vessels of the stomach are very nu- 
merous and large : they pass to the glands which 
are on the two curvatures, and from thence to the 
thoracic duct. It is an important fact relative to the 
history of digestion, that there are good reasons for 
doubting whether chyle commonly passes through 
them, notwithstanding their number and size.* 

The nerves of the stomach are derived principally 
from the two great branches of the par vagum, which 
accompany the oesophagus and are mostly spent 
upon this organ. It also receives branches from 
several plexus, which are derived from the splanch- 
nic portions of the intercostal nerves, 

SECTION 111. 

Of the Intestines. 
The intestines form a continued canal from the 
pylorus to the anus, which is generally six times 

* Sabatier, however, in one subject observed white lines on the 
stomach, which he suspected to be lacteals. See his account of the 
absorbents of the stomach. 



Villous Coat of the Intestines. 1Q5 

the length of the subject to which they belong. Al- 
though the dift'eient parts of this tube appear some- 
what different from each other, they agree in their ge- 
neral structure. The coats or laminae of which they 
are composed are much like those of the stomachy 
but the peritoneum which forms their external coat 
does not approach them in the same manner; nor is 
it continued in the form of omentum from the whole 
tube, their being only a certain portion of intestine, 
viz. the colon, from which such a process of perito- 
neum is continued. 

The Muscular Coat, like that of the stomach, 
consists of two strata, the exterior of wliich is com- 
posed of longitudinal fibres, which adhere to tlie 
external coat, and do not appear very strong. The 
other stratum, consisting of circular or transverse 
fibres, is stronger, as the fibres are more numerous. 
It is observable that they adhere to the longitudi- 
nal fibres : and they seldom if ever form complete 
circles. 

The cellular substance immediately within the 
muscular fibres resembles the nervous coat of the 
stomach in its firmness and density. It is likewise 
so arranged as to form many circular ridges on its 
internal surface, which support to a certain degree 
the permanent circular plaits of the internal coat^ 
called valvulae conniventes. 

The inner surface of the internal coat has been 
commonly compared to that of velvet, and the coat 
is therefore called villous ; but there is certainly a 
considerable difference between these surfaces ; for 
if a portion of the small intestine be inverted, and 
then suspended in perfectly transparent water, in a 
clear glass, and examined with a strong light, it will 
appear like the external surface of the skin of a 
peach, on which the down or hair-like processes are 
not so close as those on velvet On this surface. 
Vol. II. 14 



106 Lieberkuhn on the Villous Coat. 

between the villi, there are many orifices of mucous 
follicles and of exhaling vessels.* Exterior to the 
villous coat, many very small glandular bodies are 
sometimes found, which are called after their de- 
scribers Glandulse Brunneri and Peyeri. 

The internal coat of the upper portion of the in- 
testinal tube is arranged so as to form a great num- 
ber of transverse or circular folds or plaits, called 
Valvulx Conniventes^ which do not generally extend 
round the intestine, but are segments of circles ; they 
are so near each other that their internal edges, 
which are very moveable, may be laid upon the folds 
next to them, like tiles or shingles. It is evident 
that this arrangement of the internal coat must add 
greatly to its length. This coat is extremely vascu- 
lar, so that in the dead subject it can be uniformly 
coloured by a successful injection. The minute struc- 
ture of it has been tlie subject of very diligent in- 
quiry. Tliere can be no doubt but that an immense 
number of exhaling and of absorbent vessels open 
upon it ; but there are many diff'erent opinions re- 
specting the termination of one set of vessels and 
the commencement of the other. 

A very interesting account of the Villous Coat was 
published in 1744, by Lieberkuhn, who was con- 
sidered by his cotemporaries as a most expert prac- 
tical anatomist, and was also very skilful in micro- 
scopical examinations, for which he was particularly 
calculated, as his natural powers of vision were un- 
commonly strong. In his essay he refers to his 
preparations, which were at Berlin, and which ap- 
pear to have excited great surprise in the minds of 

* It appears clearly, from the account of Lieberkuhn, that the 
orifices or terminations of the arteries on the intestines, are distinct 
frj^ the follicles ; for he forced injection from the arteries into the 
cavity of the intestines, and found the follicles still filled with mu- 
cous. He then urged the injection further, and filled the follicles, 
or forced the mucous outof them. 



Hewson and others on the Filli. 107 

the members of the Academyof Sciences of Prussia, 
at a time when one of the first anatomists of Europe, 
the celebrated Meckel, was of their number. 

According to this account, the internal surface of 
the small intestines abounds with villi, and with the 
orifices of follicles. These villi are about the fifth 
part of a line in breadth. In each of them is a cavity 
filled with a soft spongy substance, which has one 
or more orifices communicating with the intestines, 
and from Avhich also proceeds a lacteal vessel. On 
the membrane which forms this cavity, blood vessels 
are most minutely ramified. This cavity he calls an 
ampuUula, and supposes it to constitute the principal 
part of the villous. By injecting the arteries of the 
intestine, he w^as able to pass a fluid through the 
ampullula into the cavity of the gut ; he kept a 
stream of air in this way passing through the am- 
pullula until it was nearly dry and stiiF, and then 
laid it open with a fine instrument. From the ap- 
pearances which then presented, he inferred that the 
cavity of the ampullula was occupied with a spongy 
or cellular substance. Around each villus he found 
a number of mucous follicles, v/hich often were filled 
Avith a tenacious mucous : and distinct from these 
must be the exhaleut orifices, which discharged a 
fluid injected by the arteries without passing through 
the mucous follicles. 

Lieherkuhn died early, and left but one essay on 
this subject, which was originally published in Hol- 
land, in 1744, but has been republished by the Aca- 
demy of Berlin, in their Memoirs; arjd also by Air. 
John Sheldon, of London. 

This account of Lieherkuhn appears to have 
been admitted by Haller; but it has been rigidly 
scrutinized by some of the anatomists of London^ 
who were particularly interested with thesubj^t; 
as they had paid great attention to the absorbent 



108 Pyf^ (^nd others on the Villi. 

system, and were very successful in the investiga- 
tion of it. 

The late Mr. Hewson, whose opinion is entitled 
to the greatest respect, rejected the idea of the aui- 
pullula, and believed that the villi are composed of 
networks of lacteals, as well as arteries and veins ; 
although he added that ^^ this is the only circum- 
stance concerning these parts in which he should 
dijffer from this very acute observer."* 

Mr. Sheldon agrees with Lieberkuhn : but Mr. 
Cruikshanks asserts, that, *• in some hundred villi, 
he has seen the lacteals originate by radiated 
branches, whose orifices were distinct, on the sur- 
face of the villous." The villous being transparent, 
when the intestine was immersed in water, these 
branches, filled with chyle, could be seen passing 
into the lacteal. Mr. Cruikshanks therefore sup- 
poses that Lieberkuhn was mistaken, and that the 
spongy cavity, or ampullula, was the common cellu- 
lar membrane, connecting together all the arteries, 
veins, nerves, and lacteals. 

It seems probable, from Mr. Cruikshanks' state- 
ment, that Dr. William Hunter held the same 
opinion with himself. And there is also reason to 
believe that Monro the second, who studied anato- 
my at Berlin, held a different opinion from Lieber- 
kuhn. 

Mr. Fyfe, who has been much employed in the 
investigation of the absorbent system, and must be 
perfectly acquainted with the preparations of Mon- 
ro, asserts that each lacteal takes its rise upon one 
of the villi by numerous short radiated branches, 
and each branch is furnished with an orifice for im- 
bibing chyle. 

Several of the late French writers adopt the opi- 

* See Hewson's Expevimental Iiiquii'ies, vol. 2, page I7y. 



Division of the Intestines. 109 

iiiou of Lieberkuhn ; but his countryman Soemmer- 
ing gives a different account of the subject. He says, 
that, besides the blood vessels, each villous consists 
of a fine network of absorbent vessels, whose ori- 
fices may be distinctly recognized ; and that from 
six to ten of these orifices are sometimes discovered. 

Mascagni, who has published the most extensive 
work upon the absorbent system that has yet ap- 
peared, supposes Lieberkuhn to have been mistaken, 
and confirms the description of Hewson : but he also 
agrees with Hewson in his opinion of the general ac- 
curacy of Lieberkuhn. 

Notwithstanding their differences respecting the 
origin of the lacteals, all these observers have agreed, 
that the orifices which communicate with the lacteals 
are on the villi ; and that these villi contain also 
very fine ramifications of blood vessels. They have 
also agreed, that the surface of the intestines in the 
intervals of the villi seems occupied with the orifices 
of ducts or of exhalent vessels.* 

Division of the Intestines. 

Although there is a considerable degree of uni- 
formity in the structure of the intestinal canal, dif- 
ferent parts of it are very distinguishable from each 
other by their exterior appearance, by their size, 
their investments, and their position. 

The first division is into two great portions, which 
are very different from each other in their diameter 
and length, as well as their situation : the first por- 
tion being much smaller in diameter, and near four 
times the length of the other. 

* On this subject the student will consult, with advantage, Hew- 
hon's Experimental Inquiries, vol. 2d; Sheldon's History of the 
Absoi-|)ent System, part 1st ; Ci'iiikslianks oi. the Anatomy of the 
Absorbing Vessels; and the Historia Vasorum Lyraphaticorum 
Corporis Ilumuni, of Mascagni. 



110 Division of the Intestines. 

These portions are therefore known by the names 
of Great and Small Intestines, and the line of sepa- 
ration between them is very strongly marked ; for they 
do not gradually change into each other, but the al- 
teration in size and in exterior appearance is very 
abrupt, and their communication is -not perfectly 
direct. A considerable portion of the Great Intes- 
tine is fixed immoveably in the abdomen, while a 
large part of the Small Intestine is very moveable. 

Each of these great portions of the intestinal tube 
is subdivided into three parts. Thus, in the Small 
Intestine, tliere is a piece at the commencement called 
Duodenum, a great part of which has no coat from 
the peritoneum, and is immoveably fixed in one situa- 
tion ; while all the remainder of the small intestine 
has a uniform covering from the peritoneum, and is 
very moveable. This last piece, notwithstanding 
its exterior uniformity, is considered as forming two 
parts. The uppermost two fifths form one part, 
which is called Jejunum; and the remainder is 
called Ileum.. The Great Intestine commences in 
the lower part of the right side of the abdomen, and 
after proceeding up that side crosses over to the 
left, along which it descends to the lower part again, 
when by a peculiar flexure it proceeds to the cen- 
tre of the posterior margin of the pelvis, from which 
it passes down to the anus. A short portion of this 
intestine, which is above its junction with the ileum, 
is called Caecum ; the part which proceeds from this, 
round the abdomen, is called Colon ; and the por- 
tion which is in the pelvis is called Rectum. 

Of the Small Intestines. 

Previous to the description of the small intestines, 
it is necessary to observe, that the Mesocolon, or 
process of the peritoneum connected to the trans- 
verse portion of the colon, forms a kind of moveable 



Commencement of the Small Intestines. Ill 

and incon»plete septum, which divides the abdomen 
into an upper and lower apartment. Above this 
septum are the stomach, with the commencement of 
the duodenum, the liver, and the spleen ; below it, 
that portion of the small intestine which is called 
jejunum and ileum, makes its appearance. The por- 
tion of the intestine which passes from the stomach 
to the jejunum, and is called Duodenum, is so much 
involved by the mesocolon, that the greatest part of 
it cannot be seen without dissecting the mesocolon 
from its connexion with the back of the abdomen.— 
For the duodenum proceeds backwards from the 
pylorus, and passing down behind the peritoneum, 
enters a vacant space between the two laminae of 
the mesocolon ; it proceeds for some distance in this 
space, and then emerges on the lower side of the 
mesocolon. Here the duodenum terminates, and 
the small intestine then is invested by the peritoneum 
in such manner as to form mesentery, which conti- 
nues with it throughout its whole course to the great 
intestine. This portion of the intestine, although 
very uniform in its exterior appearance, as has been 
observed before, is divided into Jejunum and Ileum : 
the jejunum being the upper portion, which begins 
at the mesocolon ; and the ileum the lower portion, 
which opens into the great intestine. 

Of the Duodenum. 

The length of this intestine is equal to the breadth 
of twelve fingers, and hence its name. It is very 
difi'erent from the rest of the small intestine, not only 
as respects its position and investment by the peri- 
toneum, but on account of its connexion with the 
liver and pancreas, by means of their excretory 
ducts, which open into it. From this connexion 
with these glands, probably, all the peculiarities of 
its position are to be deduced. 



#x. 



112 Situation of the Duodenum. 

When the stomach is in its natural situation, the 
pylorus is at some distance from the back of the 
abdomen. The duodenum proceeds backwards 
from this point, and passes near the neck of the 
gall-bladder, being here connected with the small 
omentum ; it then curves downwards, and descends 
before the right kidney, sometimes as low as the 
lower part of it; then it curves again, and passes 
over to the left : after it has arrived at the left side 
of the spine, at the second or third lumbar vertebra, 
it projects forwards and downwards to form the je- 
junum. The only portion of this intestine which is 
moveable, is that which is in sight as it proceeds 
immediately from the pylorus, being about an inch 
and a half, or two inches in length. The remain- 
der is connected to the back of the abdomen, and lies 
between the two laminse of the mesocolon. In its 
progress it passes before the aorta and the vena cava, 
but the principal branch of the vena portarura is 
before it. 

The duodenum is larger in diameter than any 
other part of the small intestines, and has a stronger 
muscular coat. Its general situation admits of great 
dilatation, and it has been called a second stomach. 
Its internal coat is strictly villous, in the anatomical 
sense of the word ; and its folds, the valvulse conni- 
ventes, begin at a small distance from the pylorus. 
The orifices of many mucous ducts are to be seen on 
its surface. It is supposed that some of these are 
the terminations of ducts from the glands of Brunner, 
which sometimes appear in the villous coat, or very 
close to it exteriorly ; being small flat bodies, with 
a depression in the centre, and a foramen in the de- 
pression. They are sometimes very numerous at 
the upper extremity of this intestine, and diminish 
gradually towards the other extremity. 

The biliary and pancreatic ducts open posteriorly 



Jejunum and Ileum, 113 

into the cUiodenum, rather a'/ove the miiMle of it. 
The orifice of these ducts is generally surrounded 
by a small tubercle, which is oblong, somewhat 
rounded at one extremity, and pointed at the other. 
Sometimes this orifice is in a plait, like one of the 
valvulse conniventes. Most commonly the two ducts 
unite before they perforate the coat, so as to form 
but one orifice ; and sometimes they open separately^ 
but always very near to each other. 

Absorbent vessels, which contain chyle^ are found 
on the duodenum. 

The Jejunum and Ileum 

Are situated in the abdomen very diflTerently from 
the duodenum. When the cavity is opened, and the 
omentum raised, they are in full view; and every 
portion of them, except the two extremities and the 
parts near them, can readily be moved. This free- 
dom of motion is owing to the manner in which they 
are invested by the peritoneum ; or in the technical 
language of anatomy, to the length of their mesente- 
ry. They agree in their structure with the general 
description of the small intestines, but their muscu- 
lar coat is rather weaker than that of the duodenum. 
The valvuliE conniventes are very numerous and 
large in the upper part of the tube, or the jejunum | 
and gradually diminish in number, until they finally 
disappear, in the lower part of the ileum. The vil- 
lous coat is in perfection in the jejunum, the villi 
being more conspicuous here than in any other part 
of the intestinal tube. There are frequently found, 
exterior to this coat, but intimately connected with 
it, many small glandular bodies of a roundish form, 
which are often clustered together at that part of the 
intestine which corresponds with the interstice of the 
laraiiije of the mesentery. They are called Peyer's 
glanils, after the anatomist who first described them; 

Vol. II. 15 



i 14 Distinction between Jejunum and Ileutn. 

and are supposed, like the glands of Brunner, to se- 
crete mucus. If a portion of the jejunum be inverted, 
^nd moderately distended with air, these bodies ap- 
pear very distinctly in it, dispersed at small dis- 
tances from each other. In the ileum they appear 
in small clusters, whicli often have the appearance 
of disease. 

No natural line of separation for distinguishing the 
jejunum and ileum from each other, is to be found ; 
but these names are still retained ; and therefore a 
yule laid down by Winslow is generally adopted, 
viz. to name the first two-fifths of the tube jejunum, 
and the remainder ileum. There are, however, some 
important differences between these portions of the. 
intestine. 

In the jejunum, the valvulse conniventes are so nu- 
merous, that tifey lie in contact with each other, as 
shingles on the roof of a house ; in the ileum they 
gradually diminish in number, and finally disappear. 
In the jejunum the villi are much stronger than they 
are in the ileum. 

It is very difiBcult to acquire a precise idea of the 
arrangement of this part of the intestinal tube, while 
it is in the abdomen, especially if it be much distend- 
ed ; but if it be separated at each extremity from the 
intestine with which it is connected, and the mesen- 
tery cut off from the b^ck of the abdomen, and the 
whole then spread out upon a flat surface, it will 
appear, as has been already said, that the intestine 
is arranged so as to form a semicircle or large 
curve; the concavity of which is opposite to the 
back of the abdomen, while the convexity presents 
forward. It will also appear, when thus placed 
upon a table, that the intestine, while connected 
■with the mesentery, is laid into many folds. It has 
been supposed, that the middle portion of the mesen- 
iery^ and the intestine connected with it, is generally 



Construction of the Mesentery, il5 

in the umbilical region ; and the two portions on the 
sides of it are in the iliac regions ; but their si- 
tuation in the abdomen varies considerably at differ- 
ent times. When the viscera of the pelvis are empty, 
a large portion of the small intestine is in the pelvis ; 
but wheu those viscera are filled, the intestine is in 
the general cavity of the abdomen. 

The Mesentery 

Is a process of the peritoneum, which is formed 
in the manner of a plait or fold, and of course con-* 
sists of two laminse. These laminae proceed from 
the back part of the abdomen, and are so near to 
each other, that they compose one substantial pro- 
cess ; having cellular and adipose substance, blood 
vessels and nerves, with absorbent or lacteal vessels 
and their glands, between them. 

The form of this process, when it is separated 
from the back, and the intestines are detached from 
it, is somewhat semicircular : that portion of its 
margin or edge which corresponds to the diameter 
of the semicircle, is connected to the back of the ab- 
domen, and called the root of the mesentery ; the 
edge, which is the circumference of the semicircle, 
is connected with the intestine. The edge connected 
with the back of the abdomen is commonly about 
five or six inches in length : the semicircular edge, 
instead of extending fifteen or eighteen inches, the 
ordinary proportion, is attached to a portion of intes- 
tine sometimes twenty-four feet in length. The 
mesentery on account of this great difference between 
its diameter and circumference, has been compared 
to the ruffle of a shirt sleeve ; its roots being taken 
for the plaited edge of the ruffle, and the circumfer- 
ence for its loose edge. But the comparison is not 
precisely accurate ; for the mesentery is not plaited 
at its root, but perfectly smooth, and free from every 



116 Root of the Mesentery. 

kind of fold. It begins to enlarge towards its cir- 
cumference, and enlarges to that degree, that it falls 
into plaits or folds : precisely such as would exist 
in a semicircular piece of membrane about six inches 
in diameter, if a number of simple incisions, of 
about an inch and a half in length, were made in a 
radiated direction from its circumference, and if por- 
tions like a sextant or quadrant were taken from a 
circular membrane three inches in diameter, and 
united by their edges to these incisions, so that their 
'circumference might be continuous with the circum- 
ference of the large semicircular piece. In this case, 
the portions like quadrants or sextants would as- 
sume a folded position like the edge of the mesen- 
tery, while the middle of the semicircular piece would 
preserve its regular form without folds ; as is the 
case with the mesentery at some distance within its 
circumference. By many additions of this kind, the 
circumference of a membrane, which was originally 
a semicircle of five or six inches, may be extended 
so as to exceed greatly that of the mesentery. It 
seems of course impossible to form an accurate mo- 
del of the mesentery with a single piece of membrane 
or paper ; but it may be easily made with clay, or 
any ductile substance. A model of this kind must 
necessarily be folded after the manner of the mesen 
tery ; and its circumference, like the mesentery, 
would appear as if formed of portions of the circum- 
ference of smaller circles united to each other.* 

The root of the mesentery commences with the 
jejunum on the lower side of the mesocolon, at the 
left of the spine, and extends downwards near to 
the right iliac region ; crossing the spine obliquely. 

* A model, upon the plan first mentioned, was invented by Dr 
J. G. Shippen. It has been proposed, I believe by M, Gavard, to 
make one with a single piece of buckskin, of a semicircular form, 
by stretching it at the circumference. 



Appearance of the Csecum and Colon. 117 

When it is examined in its natural situation, the peri- 
toneum is found continued from tiie back of tiie ab- 
domen to the intestine ; it then surrounds the intes- 
tine, and continues from it to the back of the abdo- 
men again. There must therefore be two laminae 
of peritoneum in the mesentery, and there must be a 
small portion of intestine answering to the interstice 
between these lamiufe, which is not covered by the 
peritoneum. The blood vessels, and absorbent or 
lacteals, pass most commodiously to the intestines 
between these laminse ; for they are connected witli 
large trunks that lie on or near the spine, and the 
root of the mesentery commences there. 

The glands connected with the lacteals or absorb- 
ents are very conspicuous in the mesentery, and are 
commonly called mesenteric glands. They are of 
different sizes, from more than half an inch to one 
or two lines in diameter. They are very numerous, 
and scattered irregularly, but are seldom observed 
very near to the intestine. They are often enlarged 
in consequence of disease, especially in children. 

Tlie nerves of the small intestines, which are 
derived principally from the superior mesenteric 
plexus, are also to be found here. 

The adipose matter between the laminae of the 
mesentery is very often in a large quantity, but 
varies in proportion to the general quantity of adeps 
in the subject. 

OF THE GREAT INTESTINES. 

The Csecum and Colon 

Are very different from the small intestines in 
many respects. They are much larger in diameter. 
Their external surface is marked by three longitudi- 
nal bands of a light colour, which extend the great- 
est part or their length, and are placed nearly at 



118 Fosition of the Csecum. 

equal distances from each other. The spaces be- 
tween these bands are marked by transverse indenta- 
tions, which pass from one baud to the other at 
short but unequal distances. At these indentations 
the coats of the intestine are pressed inwards, as if a 
fine thread had been drawn round it externally, 
while the spaces between them are full and tumid^ 
and on this account are called cells. 

The great intestine, with these appearances, be- 
gins, as has been already observed, in the right iliac 
region, by a rounded end which rests on the fossa 
or concave surface formed by the costa of the ileum ; 
from this it is continued upwards in the right lum- 
bar region, anterior to the kidney, until it arrives 
near the liver, when it forms a curve, and passes 
directly across the abdomen to the left side. In this 
course it approaches so near to the under side of 
the liver, that it is often in contact with it, and with 
the gall-bladder, which, after death, tinges it with a 
yellow colour. On the left side it passes down the 
lumbar region, before the kidney, to the left iliac 
region ; here it is curved so as to resemble the 
Roman letter S, inverted ; this curve generally car- 
ries it to the right side of the spine, and then brings 
it back to the centre of the sacrum. Here the in- 
testine changes its course, and passing into the 
pelvis, continues downward, in contact with the 
sacrum and coccygis, and partaking of the curvature 
of those bones, until it terminates at the anus, where 
it is connected with the sphincter and levator ani 
muscles. 

About two inches from the commencement of the 
great intestine the ileum opens into it laterally ; and 
all that portion which is between its commencement 
and the insertion of the ileum is termed Caecum^ or 
the blind intestine : that part of the great tube, 
which is included in its course from the insertion of 



Structuye of the Colon. 119 

file ileum to the posterior part of the brim of the 
pelvis, is called Colon; and the remainders or the 
part which is contained in the pelvis^ is termed Rec- 
tum. 

The Csecum is nearly as wide as it is long ; it is 
fixed in the right iliac fossa by the peritoneum, 
which invests it so that the great body of the intes- 
tine projects from the surface of the fossa covered by 
the peritoneum ; but a portion is in close contact 
with the surface, and connected to it by cellular 
membrane. Its external surface, covered by the 
peritoneum, is marked by two of the bands or 
stripes before mentioned, which proceed on it length- 
ways. These bands are in full view, but the third 
band is generally on that part of the intestine which 
rests on the iliac fossa, and is therefore out of sight. 
At the rounded extremity of the csecum, situated 
anteriorly and internally, is a small process resem- 
bling an earth-worm in form and size : this is there- 
fore called Appendicula Vermiformis. It is hollow, 
and communicates with the cavity of the csecum at 
the place of junction; and like the cascum, has its 
other extremity closed up. It is composed of the 
same number of coats and has the same structure as 
the great intestine : its length varies from two to four 
inches. 

The longitudinal bands above mentioned com- 
mence at the junction of this appendix with the 
csecum, and continue throughout the extent of the 
colon. They appear to be formed by some of the 
longitudinal fibres of the muscular coat, which are 
arranged close to each other. These fibres seem to 
be shorter than the coats of the intestine, and the in- 
terior coats adhere firmly to them. Thus are pro- 
duced the indentations and cells ; for if the bands 
are divided transversely, the indentations disappear, 



120 Valve of the Colon. 

and the surface of the intestine becomes uniform. 
One of these bands is covered by the mesocolon. 

The circular or transverse fibres of the muscular 
coat of the csscum and colon are very delicate, and 
not numerous. 

The internal coat diflfers materially from that of 
the small intestines, although at first view they 
seem to resemble each other : for if a portion of the 
ileum and of the colon be inverted and suspended in 
water, no villi can be seen with the naked eye on 
the internal coat of the colon, while those of the ileum 
are very visible. The glands exterior to this coat 
are larger than those on the small intestines. 

Instead of valvulse conniventes, are the ridges 
made by the indentations or depressions above des- 
cribed, which separate the incomplete cells from each 
other. These ridges differ essentially from the val- 
vulae conniventes, because all the coats of the intes- 
tine are concerned in their formation, whereas the 
valvulai conniventes are formed by the villous coat 
only ; they also project into the cavity of the intes- 
tine, while the valvulse are laid on its surface. They 
pass only from one longitudinal band to another, 
and, in consequence of this, the cells are small, and 
the position of each band is very evident when the 
intestine is laid open. 

The communication of the ileum with the great 
intestine has been already stated to be on the left 
side of it, about two inches from its commencement. 
The aperture is so constructed, that it is considered 
as a valve, and is called the Valve of Bauhin, or of 
Tuipius, after the anatomists who have described 
it.* The appearance of tlie aperture is as follows ; 
If the csecum, with a small portion of the ileum and 

* Posthius in 1566 ; Vidus Vidius about 1569 ; Alberti in 1581, 
and Varolius who died in 1575, each lay claims to the discovery of 
it. Bauhin's claims are in 1579. Ed. 



Structure of the Valve of the Colo?i. 121 

of the colon, be separated from the other intestines, 
and kept in an inflated state until it be so dry as to 
preserve its form when opened, and then if the cae- 
cum and colon be laid open opposite to the aperture 
of the ileum, a large, transverse ridge, resembling 
some of the ridges or folds just described, will be 
seen projecting into the cavity of the intestine. In 
the internal edge of this fold is along slit or opening, 
which forms the communication between the two in- 
testines. It is obvious that the form of this fold must 
be that of a crescent ; and that its two surfaces with* 
the slit between them, must have the appearance of 
two lips, which would readily permit a fluid or sub- 
stance of soft consistence to pass from the ileum into 
the great intestines, but must impede, if not prevent, 
its passage back ; especially if the large intestines 
were distended, as then' the lips would be pressed 
against each other. 

When the peritoneal coat is dissected from each 
of the intestines at their place of junction, and this 
structure is then examined from without, it appears 
as if a transverse or half circular indentation had 
been formed by tlie villous coat of the great intestine^, 
and that the internal coat of the extremity of the 
ileum was pressed into this indentation, and united 
to the internal coat of the great intestine which form- 
ed it; while there was a slit, both in the indentation 
and in the end of tiie ileum, which formed a commu- 
nication between the cavity of the great intestine and 
the ileum. The longitudinal fibres of both intestines, 
as well as their external coats, seemed to be united, 
so as to form a common cover for them ; while the 
circular fibres were blended in the two portions of 
the indentation which form the lips of the orifice. 

This orifice is, of course, transverse with respect 
to the intestine. It has been observed, that there 
was a difi'erence in the thickness and strength of the 

Vol. 11. 16 



1^2 Position of the JRectu?n. 

two lips or valves; that the lower valve was the 
strongest, and appeared to have the largest propor- 
tion of muscular fibres in its composition. x\t the 
extremities of the orifice, and near each end of the 
fold or ridge, are tendinous fibres, which give 
strength to the structure ; they are called the Reti- 
iiacula of Morgagui, as they were first described by 
that anatomist. 

There is great reason for believing that this valve 
cannot prevent the retrograde motion of the contents 
pf the intestines in all cases ; for in some instances of 
hernia and of colic, matter perfectly stercoraceous 
has been vomited, and the probable inference from 
such a state of the ejected matter is, that this matter 
has been in the large intestines. It is also said, that 
suppositories and enemata have been discharged by 
vomiting. 

On the right and left sides of the abdomen, the 
colon is in close contact with the posterior surface of 
the cavity. The peritoneum, which covers this sur- 
face, extends over the intestine also, and thus retains 
it in its position. The great arch of the colon, which 
is loose and moves far from the back of the abdomen, 
is invested by the two laminae of the omentum, 
which, after surrounding it, unite again and form 
mesocolon. Connected with the exterior surface of 
the colon are many processes, composed of adipose 
membrane, varying in length from half an inch to an 
inch and a half: these appear to be of the nature of 
the omentum, and are therefore generally denomi- 
nated Appendices Epiploicae. 

The Rectu7n. 

After forming the sigmoid flexure, the colon ter- 
minates ; and the rectum begins opposite to the low> 
cr surface of the last lumbar vertebra, and nearly in 
contact with it : from this it proceeds downwards, 



Structure of the Bectwn» 1S3 

forming a curve like the sacrum, until it terminates 
at the anus, where it is invested with the muscles 
called the sphincter and levator ani. tt is called rec* 
tum, because in this course it is supposed not to in- 
cline to either side ; but it is often found on one side 
of the middle line.* 

This intestine being in contact with the posterior 
surface of the pelvis, is covered, on its anterior sur- 
face only, by the peritoneum which lines the poste- 
rior surface of tlie pelvis ; and it is fixed in this 
situation by the peritoneum, as the colon is on the 
right and left sides of the abdomen, but more loose- 
ly ; and therefore the term Mesorectum has some- 
times been applied to that portion of the peritoneum 
which is analogous to the mesentery and mesocolon. 
The peritoneum does not extend to the end of the 
rectum : for it is reflected at the lower part of the 
pelvis from the rectum to the bladder, or uterus, and 
does not line the bottom of the pelvis ; so that the 
lower part of this intestine, as well as of the other 
viscera of the pelvis, is below the peritoneum, and 
not connected with it. 

The muscular coat of the rectum is much thicker 
and stronger than that of any other intestine. The 
strata of longitudinal and circular fibres which com- 
pose it are very distinct from each other. The lon- 
gitudinal fibres are most numerous, and terminate at 
the insertion of the fibres of the levator ani muscle. 
The lower circular fibres are intimately connected 
with the sphincter ani. 

The internal coat is very vascular, but the villous 
structure is not apparent. Mucous follicles are also 
very numerous ; and there are likewise some distinct 
glandular bodies exterior to this coat, which vary in 
size in different subjects. 

• Morgagni and Haller supposed it to be commonly on the left 
of the middle line : and Sabatier on the right. 



124 Ahsorhenis and JVerves of the Intestines, 

The quantity of mucous dischai'ged from the rec- 
tum in certain cases of disease, is sometimes very 
great. The internal coat, in consequence of tlie con- 
traction of the circular fibres exterior to it, some- 
times forms longitudinal folds, which have been 
called its columns ; these often disappear when the 
intestine is opened lengthways and spread out. By 
the contraction of the longitudinal fibres, the internal 
coat is often thrown into folds or doublings, that 
must assume a transverse or circular direction ; they 
occasionally pass down through the sphincter, and 
form the prolapsus ani. The rectum is most plenti- 
fully supplied with blood vessels, to be described 
hereafter ; and it may be observed, that, on the lower 
part of the internal coat, the veins ai*e particularly 
numerous. 

The internal coat of the rectum terminates ab- 
ruptly just within the anus, arid is united to a pro- 
duction of the skin, which, like the covering of the 
lips, is very delicate and vascular, and has an epi- 
thelium, or very thin cuticle, spread over it. The 
levator and sphincter ani muscles, with which the 
termination of the rectum is invested, are described 
in the first volume. 

The Absorbents of the Jjitestlnes are commonly 
denominated Lacteals.* They originate on the iri- 
ternal surfaces of these viscera, as has been already 
described. After passing through the lymphatic 
glands, which are so numerous on the mesentery, 
they generally unite and form one of the great trunks 
which compose the thoracic duct. It is asserted, 
that some of the absorbent vessels of the lower in- 
testines unite to the lymphatics of the loins. 

* The lacteals were first observed by Erasistratus and Herophi- 
lus, of the school of Alexandria, during the reign of the Ptolemies ; 
and subsequently by Asellius, of Pavia, in 1622, the knowledge of 
them having been lost for 19C0 year.— Ed. 



Origin and Arrangement of the Omentum. 125 

The J^erves of the Intestines are principally de- 
rived from the intercostals, or sqreat sympathetics. 
From each of these nerves, while they are in the 
thorax, an important branch, called the ramus splanch- 
nicus, arises. These splanchnic branches pass through 
the diaphragm, and are the chief contributors to the 
ganglions and plexuses formed in the abdomen. A 
plexus, derived from this source surrounds the supe- 
rior mesenteric artery, and another the inferior me- 
senteric ; and from these proceed the nerves of the 
intestines. 

The Omentum 

Requires a separate description, although several 
circumstances connected with its structure have been 
already noticed. It often varies in its position ; but 
when it is rendered firm by a quantity of adipose 
"Inatter, it is spread over the intestines like an apron, 
extending from the lower edge, or great curvature of 
the stomach, towards the bottom of the abdomen. 

As has been already said, it is an extension of the 
peritoneum, in two laminse, from the concave surface 
of the liver to the lesser curvature of the stomach ; 
and these laminae, after surrounding the stomach, 
come in contact with each other near its great curva- 
ture. From this portion of the stomach, from the 
commencement of the duodenum, and also from the 
spleen, the Omentum, composed of two laminse, de- 
scends over the colon and the small intestines more 
or less low into the abdomen ; it is then folded back- 
wards and upwards, and is continued until it meets 
the great arch of the colon : here the laminaj again 
separate and inclose that portion of the intestine, on 
the posterior side of which they again approach each 
other, and form a membrane like the mesentery, of 
two laminae, which passes from the concave or pos- 
terior surface of the colon to the back of tlie abdo- 



126 Origin and Arrangement of the Omentum. 

men, where it is continued into the membrane which 
lines that surface. This last portion \& iho. Mesoco- 
lon: the portion between the liver and stomach is 
called the Omentum of TVinslow, or the lesser 
omentum ; and the great portion between the sto- 
mach and colon is called the Great Omentum, or the 
omentum gastro colicum. There is also a process 
of peritoneum continued from that portion of the 
colon which is on tlie right side of the abdomen, and 
from the csecura, which extends to some distance ; 
it is formed of two laminsB, that compose a cavitj of 
an angular form. This has been called the Omen- 
tum Colicum. 

The great and small omentum, with a portion of 
the peritoneum on the back of the abdomen, form a 
sac, which incloses a distinct cavity in the abdomen. 
The anterior part of this sac is composed of two 
lamina, and between these laminae are the stomach 
and the great arch of the colon. This cavity, form- 
ed by the two omenta, communicates with the gene- 
ral cavity of the abdomen by a foramen of a semicir- 
cular form, called the Foramen of Winslovv, which 
is behind the great cord of the vessels that go to the 
Uver. 

The omentum is so delicate in structure, that 
when free from fat, it is very liable to laceration 
merely by adhering to the fingers, if they are dry. 
Winslow therefore advised that some unctuous sub- 
stance should be rubbed on the hands, before they 
were applied to it. 

The appearance of the great omentum is very dif- 
ferent in different persons. In the emaciated, it 
appears like a delicate transparent membrane; in 
the corpulent, it is like a broad mass of adeps, which 
sometimes is very thick. When it is thus loaded 
with adeps, it is most commonly spread over the 
small intestines : when itis free from fat, it is often 



Varieties in the Appearance of the Omentum. 127 

compressed together, so as to form a small mass 
near the arch of the colon, on the left side. 

The principal blood vessels of the omentum are 
derived from those of the stomach, and are called 
gastro epiploic arteries and veins. 

The use of this membrane in the animal economy 
has not been ascertained with certainty. It seems 
probable that one of its principal objects is to pro- 
tect the small intestines, and lessen the friction con- 
sequent upon their motion ; but it has been supposed 
to answer several other important purposes.* 

*See HalleriElementa Physiologise, vol. VI. page 381. 

Gavard. Traite de Splanchnologie, page 350. 

Dr. James Rush's Inquiry into the use of the Omentum. 



CHAPTER III. 

OF THE LIVER, THE PANCREAS, AND THE SPLEEN. 
SECTION I. 

Of the Liver. 

This largest viscus of the abdomen, when in a 
healthy condition, is of a reddish brown colour. 
If it is taken out of the subject, and laid on a flat 
surface, it is flat, but in the abdomen it is convex 
and concave. 

It is situated in the right hypochondriac region, 
which it occupies entirely ; and extends through the 
upper portion of the epigastric into the left hypo- 
chondriac region. Being placed immediately under 
the diaphragm, and in close contact with it, as well 
as with the inner surface of the right hypochondriac 
region, it partakes of their form, and is convex above 
and concave below. When thus situated, it is of 
an irregular figure, between the circle and the oval, 
but it is broader at the right extremity than at the 
left, and very irregular in thickness. The edge or 
margin which is in contact with the posterior part 
of the right hypochondriac region, is very thick. It 
gradually becomes thinner towards the left, and also 
towards the front; so that the right margin, and a 
large portion of the posterior margin, is very thick, 
while the left and the anterior margin is thin. 

The upper convex surface of the liver, when in 
its natural situation, is smooth : the lower concave 
surface is marked by several grooves or fissures and 
eminences. One of these, called the Umbilical or 
the great fissure, commences at a notch in the ante- 



Lobes and Fissures of the Liver. 129 

i-ior edge of the liver, to the left of the middle, and 
continues to the posterior edge. At the conimence= 
ment of this fissure the umbilical ligament enters ; 
and at the termination, or near it, the vena cava is 
situated. Opposite to this fissure, on the upper or 
convex surface, is a ligament passing from the dia- 
phragm to the liver, which is called the falciform. 
The fissure and the ligament divide the liver into 
its two 2;reat lobes, the Right and Left. 

Another great fissure, called the transverse or 
principal, commences in the right lobe and extends 
to the left, crossing the first mentioned fissure at 
right angles, and extending a very short distance 
beyond it. It is very deep, and rather nearer to 
the posterior than the anterior edge of the liver. In 
this fissure, near to its right extremity, the great 
vein, called vena portarum, and the hepatic artery 
enter, and the excretory duct of the liver, commonly 
called the hepatic duct, comes out. About the mid- 
dle of the fissure are two prominences, one on each 
side ; these were called the portae, or gates of the 
liver, and hence the great vein was called vena por- 
tarum. This vein has two very large rectangular 
branches, which constitute what is called the sinus 
of the vena portarum, and they occupy the principal 
extent of the fissure. 

The liver is in close contact with the vena cava 
behind ; and there is either a groove in it for the pas- 
sage of the vein, or this great vessel is completely 
inclosed by it. There is also an excavation on the 
lower surface of the liver, which is occupied by a 
portion of the gall bladder. 

Besides the great lobes above mentioned, there 

are also two or three prominent parts on the concave 

■ surface, which are denominated lobes. One of these, 

called Lobulus Spigelii, is oblong, with two sides, 

%nd an angle continued along its wliolc length, 

Vol. II. 17 



130 Ligaments of the Liver. 

which extends from the transverse fissure to i\\% 
posterior margin of the liver. It is situated between 
the posterior part of the transverse fissure, or ductus 
venosus, and the vena cava. 

The anterior extremity of this lobe, which forms 
one of the margins of the transverse fissure, is some- 
what bifurcated, and has been called lobulus cauda- 
tus. The largest portion of the bifurcated end forms 
a process like a papilla, and is one of the portse. 

Between the umbilical fissure and the depression 
for the gall bladder is a protuberant space, which 
varies from an inch and a quarter to two inches in 
breadths This has also been called a lobe, Lobulus 
Quartus or Jinonymus, its posterior point opposite the 
papilla of the lob. spig, forms the other porta of the 
liver. 

The peritoneum is extended from the surface of 
the abdomen to the surface of the liver, in such man- 
ner as to cover it, and to form ligaments, which have 
a great effect in retaining it in its proper situation. 
The whole posterior edge of the liver is in contact 
with the back of the abdomen. The peritoneum 
above the liver is reflected to the upper surface of it, 
jind the peritoneum below it to the lower surface ; 
so that tw<^ laminae of the peritoneum pass from the 
lower part of the diaphragm at the back of the ab- 
domen to the posterior edge of the liver. These 
processes of the peritoneum are considered as form- 
ing two ligaments, which are called the right and 
hft lateral ligaments, A portion of the posterior 
surface of the liver, uncovered by the peritoneum, is 
often in contact with a portion of the tendon of the 
diaphragm, also uncovered by peritoneum : around 
this place of contact, the peritoneum is extended from 
the diaphragm to the liver, and thus forms what has 
been called the coronary ligament of the liver. 

The peritoneum of the right side of the diaphragm, 
and of the abdominal muscles; as far down as the 



Mode of supporting the Liver, i3i 

umbilicus, is extended to the liver, and joins it on 
the convex surface iainiediately opposite to the um- 
bilical fissure. The peritoneum fiom the left side of 
these parts does the same ; and as these reflections 
of the peritoneum are continued from so low a part 
as the umbilicus, they are extended not only to the 
convex surface of the liver, but also to the great 
notch, and alon^ the umbilical fissure. 

From the umbilicus proceeds around cord-like li- 
gament, which in the foetal state was a vein, that 
passes to the great fissure of the liver, and along it. 
The process of the peritoneum above mentioned is 
so connected with this cord, that it incloses it in its 
lower edge, and the whole is called the falciform 
ligament of the liver. The cord, when named se- 
parately, is the umbilical or the round ligament ; and 
the membrane or laraiuse of the peritoneum forms 
the suspensory ligament. Besides these, the perito- 
neum on the lower side of the liver is so arranged, 
that it not only extends to the stomach, but to the 
duodenum and the colon. 

By these ligaments the position of the liver must 
be fixed to a great degree ; and there is one addition- 
al connexion, which must have a great effect in re- 
taining it in its proper situation. The vena cava 
receives two or three great veins from the liver, at 
the place where it is in contact with the posterior 
edge of that viscous ; these veins of course pass di- 
rectly from the substance of the liver into the cava, 
and connect it to that vessel. As the cava is sup- 
ported by the heart, and also by the diaphragm, it 
must afford a considerable support to the liver. 

When the stomach and intestines are distended, 
they must also contribute in a considerable degree 
to the support of the liver. 

Tiie liver has a strong tendency, when we are 
erect, to change its situation ; and some considerable 



IBS Acini of the Liver. - — Pro'per Coat of the Liver. 

support is necessary to counteract this tendency. It 
would move to the right, when we lie on the right 
side, if it were not in contact with the ribs ; and it 
inclines to the left, for want of such support, when 
we lie on the left side. 

It has been computed, that the liver descends 
about two inches, when the position of the subject is 
changed from the horizontal to the erect. As it is 
in contact with the diaphragm, it is obvious that it 
must be influenced by the motions of that muscle, 
and that it must descend when the diaphragm con- 
tracts. 

The liver is composed of a substance which has 
some firmness of consistence, although it is yielding; 
and is also somewhat brittle or friable.* When cut 
into, the sections of many tubes, or vessels of dif- 
ferent diameters, appear on the cut surface. When 
the texture of this substance is more closely ex- 
amined, it appears somewhat granulated, or com- 
posed of very small bodies, which were called acini 
by the anatomists who first described them. The 
whole substance is inclosed by the peritoneum, which 
is extended to it from the surface of the abdomen in 
the manner that has been already described. It has 
also a proper coat or capsule ; and on the posterior 
edge, where the laminsB of the lateral ligaments pass 
from the diaphragm to the liver, at some distance 
from each other, a portion of the liver, covered by 
this coat and by cellular substance, is in contact 
with the diaphragm. The same thing occurs like- 
wise at the coronary ligament.f 

The liver holds the first place among the glands 

* It has been fractured in the living body by external violence. 

f Many anatomists deny the existence of this coat ; but if one of 
the laminx of the ligaments be carefully peeled off from the sur- 
face of a liver which is shghtly affected by putrefaction, it 'vill be 
apparent, although very thin. It was described by M. Laennec.-, . 
in Le Journal de Medecine for 180?, 



Vessels of the Liver, — Hepatic Artery. 133 

ef the body f >r si^e, but it is still more remarkable 
for some other circumstances in its economy. In 
addition to an artery, which passes to it as arteries 
do to other glands, there is a large vein which also 
enters it as an artery ; and after ramifying through- 
out the liver, communicates, as does the artery, with 
other veins, which carry the blood from this gland 
into the vena cava and the general circulation. There 
are therefore three species of blood vessels in the 
liver ; and with these are found the vessels which 
carry out of the gland the fluid secreted by it, or 
the bile. 

The artery of the liver is denominated the Hepatic 
Artery. The vein which goes to the liver is called, 
the Vena Portarum, from the place at which it en- 
ters. The veins which carry to the vena cava the 
blood brought to the liver by the hepatic artery and 
the vena portarum, are called the Hepatic Veins; 
and the duct through which the bile flows out of the 
liver, is called the Hepatic Duct. Three of these 
vessels, the Hepatic Artery, the Vena Portarum, 
and the Hepatic Duct, enter the liver at the great 
fissure, at the spot where the prominences exist 
called the portai; hence the name vena portarum 
was applied to the vein. 

These vessels ramify in the manner presently to 
be described ; and it is ascertained by minute ana- 
tomical investigation, that the liver is entirely com- 
posed of the ramifications of these vessels and of the 
hepatic veins, with absorbent vessels and nervesy 
which are connected together by cellular membrane. 

It has been already observed, that the first great 
branch sent off by the aorta in the abdomen, the 
Cceliac, divides into three branches, which go re- 
spectively to the stomach, the liver, and the spleen. 

The Hepatic is generally the largest of these 
branches. In its progress towards the liver it sends 



134 Vetia Portarurn* 

off an artery to the stomach, called the gastrica dex- 
tra. At the great fissure it divides into two branches : 
the right branch, which supplies the right lobe of 
the liver, is of course the largest. This branch 
sends off one to the gall bladder, which is called 
the cystic artery ; and also some smaller branches : 
it passes under the hepatic duct, and ramifies through 
the great lobe of the liver. The left branch is dis- 
tributed through the left lobe of the viscous. It can 
be proved by injection, that the hepatic artery com- 
municates not only with the hepatic veins, but with 
the biliary duct, and the vena portarum also. It has 
been disputed whether the size of this artery is 
greater than would be requisite for the nourishment 
and animation of the liver. 

The Vena Portarum, the great peculiarity of the 
liver, originates from all the chylopoietic viscera ex- 
cept the liver, and is of course formed by the union 
of the veins which correspond to all the branches of 
the celiac and mesenteric arteries, as they are dis- 
tributed to the stomach and intestines, the spleen, 
the pancreas, and the omentum. The veins from 
the intestines generally form two great trunks, which 
are denominated the greater and lesser mesenteric 
veins. The great mesenteric vein is situated to the 
right, and rather before the mesenteric artery. — ■ 
After it has approached the origin of the artery it 
separates from it, and passes behind the pancreas : 
at this place, nearly in front of the spine, it is joined 
by the great vein of the spleen, which forms almost 
a right angle with it, and these constitute the great 
trunk, of the vena portarum. The lesser mesenteric 
vein, which corresponds to the inferior mesenteric 
artery, and brings blood from the pelvis and from 
the left part of the colon, becomes finally a large 
vessel, and commonly unites with the splenic about 
an inch and a half before its junction with the supe- 



Vena Portarum. — Hepatic Duct. 185 

iior mesenteric vein. The vena portariinij thus 
formed, proceeds towards the liver, inclining to the 
right, and is generally about three inches in length : 
in its course it sometimes receives small veins, which 
in other cases pass to its splenic and mesenteric 
branches. When it has arrived at the great trans- 
verse sinus of the liver, it divides into two lar^c; 
branches, each of which forms nearly a right anglti 
with it. Their size is so great, that, when distended 
with injection, they appear like an independent 
vessel, into which the vina portarum enters ; and on 
this account they are called the great Sinus of the 
vena portarum. They do not adhere firmly to the 
glandular substance of the liver, but are united to it 
by cellular membrane. The right branch is the 
^videst and shortest. It generally divides into three 
branches ; an anterior, a posterior, and a lateral 
branch ; which ramify minutely, and extend them- 
selves in the right lobe. The left branch is much 
longer, and continues to the extent of the transverse 
fissure. Near its termination it is joined by the 
umbilical ligament, which has been already men- 
tioned. This branch is generally in contact with a 
branch of the hepatic artery and of the hepatic duct ; 
and ramifies, like the right branch, into the conti- 
guous parts of the liver. 

The Hepatic or excretory duct originates, by very 
small vessels, from the acini or corpuscles of which 
the liver is composed, and into which the minute 
ramifications of the vena portarum and hepatic arte- 
ry extend. They accompany these vessels, increas- 
ing as they increase, although the fluid they con- 
tain moves in an opposite direction ; and two large 
branches which they ultimately form are situated at 
the portae of the liver, in contact with the great 
branches of the vena portarum and the hepatic artery. 

These three vessels are in contact with each other 



136 Hepatic Veins. — JVerves of the Liver, 

before they enter the liver. The biliary duct is an- 
terior, the vena portarum posterior, and the artery 
to the left of thera. They are accompanied by 
nerves and lymphatic vessels, and are surrounded 
by a considerable quantity of cellular substance, 
and thus arranged are partially covered with perito- 
neum. The cellular substance which invests them 
continues with them into the liver, and is more 
particularly connected with the vena portarum. It 
is called Glisson^s Capsule, and was supposed to 
have some contractile power, which assisted the cir- 
culation of the vena portarum ; but that idea is now 
altogether abandoned. The hepatic veins, which 
receive the blood of the hepatic artery and the vena 
portarum, open into the anterior part of the vena 
cava, where it is in contact with the liver. Gene- 
rally there are three of these veins, but sometimes 
there are only two ; in which case one of them is 
formed by two others, which unite immediately be- 
fore they open into the vena cava. It is to be 
observed, that the various branches of these veins 
do not accompany those branches of the vena porta- 
rum or hepatic artery to which they correspond, but 
form very large angles with thera. This is proba- 
bly ov/ing merely to their termination in a part so 
distant from that in which the artery and the vena 
portarum originate; but it is very different from 
what occurs in other glands. 

The JVerves of the Liver are derived from the 
semilunar ganglions of the splanchnic nerves. From 
these many nerves proceed, which form a network 
denominated the solar plexus. From this plexus 
many threads are sent off, which form a network 
that is divided into the right and left hepatic plexus. 
These plexuses surround the hepatic artery and the 
vena portarum, and accompany them in their ramifi- 
cations throughout the liver; being inclosed by (xlis- 



Lymphatics. 187 

son^s capsule. They receive some threads from the 
stomachic plexus, formed by the par vagum. Al- 
though the number of nervous fibres is very consi- 
derable, their bulk, compared with that of the liver^ 
is very small. 

The Lymphatics of the Liver are extremely nu- 
merous ; and those in that portion of the peritoneum 
which invests the liver may easily be rendered con- 
spicuous : for by pressure the injected fluid can be 
forced from the trunks and large branches into the 
small ramifications, in opposition to the valves. 
When all the surface is injected in this manner, it 
has the colour of the substance injected ; as is the 
case with parts which are very vascular, when the 
blood vessels are injected. 

The deep seated lymphatics are also very nume- 
rous in the liver, and communicate freely with the 
superficial. 

The superficial lymphatics which are on the upper 
surface, proceed through the diaphragm into th^ 
thorax in their course to the thoracic duct. Those 
which are deep seated emerge from the liver at the 
portse, where the great vessels enter, and unite with 
the thoracic duct in the abdomen, after passing 
through several glands. The lymphatics of the 
lower surface unite with the deep seated. 

The glandular or parenchymatous substance of 
the liver is of a reddish brown colour, and mode- 
rately firm consistence. When it is cut iuto, the 
cut surface exhibits the sections of the branches of 
the different blood vessels above mentioned, and of 
the excretory ducts. These vessels are often distin- 
guishable from each other. The section of the 
biliary' duct appears the thickest ; that of the artery 
next ; the vena portarum is next in order ; and, last 
of all, the venae hepaticse. 

The branches of the vena portarum are surrounded 

Vol. II, 18 



138 Glandular Substance of ike Liver, 

by cellular substance, or Glisson's capsule ; and 
therefore adhere less to the substance of the liver 
than the branches of the hepatic veins. The sec- 
tions of the hepatic ducts have often bile in them, 
and are therefore termed pori biliarii. The branches 
of t!ie artery are also very distinguishable. 

When the internal substance of the liver is brought 
into view, and examined accurately, it appears to be 
formed of small bodies, or acini, v.hich are distin- 
guishable from each other. If the liver iiappens to 
be torn or lacerated, the lacerated surfaces are rough 
and irregular, owing to the separation of these acini 
iTom each other. 

It is asserted by several microscopical observers, 
tjiat a minute branch of each of the aforesaid vessels 
can be traced into each of the acini. It is also de- 
4ilared, that if each of these vessels be injected se- 
parately witli mercury, oil of turpentine coloured,, 
or a saturated aqueous solution of gutta gamba, there 
is no part of the glandular mass as large as a grain 
of mustard seed in which these vessels will not be 
found. 

Several anatomists of the first character have 
likewise declared, that a fluid properly injected into 
one of these vessels, will occasionally pass into all 
of them. Thus an injection will not only pass from 
the vena portarum to the biliary duct, but to the hepa- 
tic artery and veins also. It will likewise pass, in a 
retrograde course, from the biliary ducts to the vena 
portarum, j^nd to the hepatic artery and the hepatic 
veins ; or from any one of the four orders of vessels 
into the three others.* 

The great peculiarity of the liver is, that venous 
blood, instead of arterial, is brought to it for the 
j^urpose of secretion. Thus, the great vein of the 

* I have tried the experiment and find tlje assertion to be cor- 
rect— Ed. 



Peculiarity of the Liver. — Gall Bladder. 139 

chylopoietic viscera, instead of passing to the cavr.j 
enters tiie liver by tlie transverse fissure, anil takes 
on the office of an artery ; its coats, on tliis accoHnt, 
being much thicker and stronger than those of the 
hepatic veins.* 

The Biliary or Hepatic Duct is formed of very 
minute vessels, which originate in the acini above 
described: these unite together like veins until they 
form considerable branches, which finally compose 
the great ramifications of the biliary duct. This 
duct is very strong and firm, and on its internal sur- 
face are the orifices of many mucous foiiicles or 
ducts. It passes from the transverse fissure of the 
liver, with the hepatic artery, as before described, 
and, at the distance of an inch and a half or two 
inches from the fissure, it unites with a duct from 
the gall bladder, which is called the Cystic Duct. 
This duct is nearly equal in length to the hepatic, 
and after running almost parallel to it, at length 
unites so as to form an acute angle with it. The 
cystic duct is smaller than the hepatic, and they 
unite much like two branches of an artery. 

The Gall Bladder, from which the cystic ducf; 
arises, has the shape of a pear, with a very long 
neck, curved in a way to be hereafter described. It 
is situated in a superficial pit or cavity in the con- 
cave surface of the right lobe of the liver ; and its 
fundus, or basis, often projects a small distance be- 
yond the anterior edge of the viscus. Its position 
is such, that it extends from before backwards, and 
inclines rather to the left; of course, therefore, when 
the subject lies on his back, th© bottom of the blad- 
der is the uppermost part of it; when he lies on the 

♦ A case is related by Mr. Abernethy, in the London I'hilosophi- 
cal Transactions, in which the vena portarum terminated in the 
vena cava below the liver, witliout communicating with it. The 
hepatic artery was the only vessel which carried blood to the organ, 
and was unusually large ; the liver buing nearly of the natural size, 
^onie bile w.-^s in the gall bladder, but it was less acrid llir\n risuaj.. 



140 Gall Bladder. 

left side, it is also higher than the neck ; and when 
he lies on the right side, it is the lowermost. 

The gall bladder consists of an internal coat, and 
one that is cellular or nervous, and has somewhat 
of a fibrous appearance. This coat connects the gall 
bladder to the surface of the pit or cavity in which 
it lies. The peritoneal coat of the liver is extended 
from the surface of the viscous over that part of the 
surface of the gall bladder which is not in contact 
with it. 

The internal coat has a peculiar structure, with a 
faint resemblance to that of the villous membrane. 
It is so arranged as to form very fine folds, which 
have various directions : in some places they make 
a network ; in others, as the neck of a bladder, they 
are longitudinal. Many mucous follicles exist on 
its internal surface. 

The neck of the gall bladder is suddenly bent 
down or curved upon itself, and twisted, so that it 
resembles the neck of the swan, when the head of 
that bird is applied to one side of its breast. 

A branch of the hepatic artery, which leaves it 
before it enters the liver, is appropriated to the gall 
bladder, and is therefore denominated the cystic 
artery. The veins corresponding to this artery empty 
themselves into the vena portarum.^ The lympha- 
tic vessels are united to those which are found on 
the lower surface of the liver, and the nerves are 
derived from the hepatic plexus. 

The gall bladder appears to be merely a reservoir, 
into which bile passes through its duct in a retro- 
grade direction. If air be blown through the he- 
patic duct from the liver, it will pass to the gall 
bladder almost as freely as it passes to the duode- 
num. 

* It has been justly observed by John Bell, that the veins would 
not terminate thus, if bile were secreted by the gall bladder. 



Ductus Communis Choledochus.-'— The Bile. 141 

The biliary duct from the liver, after receiving the 
duct from the gall bladder, takes the name oi Ductus 
Communis Choledochus. It is wider than either of 
the other ducts, and near three inches in length. It 
passes down before the vena portarum, and on the 
right of the hepatic artery, to the posterior surface of 
the right extremity of the pancreas. It passes 
through a small portion of that gland, and then per- 
forates the muscular coat of the duodenum ; after 
which it proceeds from half an inch to an inch be- 
tween this coat and the villous, and opens into the 
cavity of the intestine. The orifice forms a tubercle 
which extends lengthways of the intestine, and is 
rounded above and pointed below, with a slit in it. 
While this duct is in contact with the pancreas, a 
duct from that gland generally opens into it, so that 
the biliary and pancreatic fluids enter the duodenum 
by the same orifice ; but sometimes the pancreatic 
duct opens into the duodenum by a distinct orifice, 
very near to that of the biliary duct. 

The Bile, or fluid secreted by the liver, appears to an- 
swer a two-fold purpose in the animal economy. It 
produces a chemical effect upon the alimentary mix- 
ture which passes from the stomach through the intes- 
tines ; and it increases the peristaltic motion of those 
important organs. 

By an inverted action of the duodenum, some of this 
fluid is frequently carried upwards into the stomach : 
it then often produces only slight derangement of the 
functions and sensations connected with that viscous; 
but sometimes violent vertigo, and even convulsions^ 
seem to have arisen merely from the presence of a 
large quantity of bile in the stomach : for they have 
gone off completely upon the discharge of bile by 
vomiting. 

Notwithstanding these effects of bilo in certain 
cases, in which a great deal of it exists in the sto- 
mach, it is often carried into tlie mass of blood in 
large quantities, and appears to he mixed with ih". 



142 The Panc)*eaSc 

serum, and to circulate through the body, without pro- 
ducing any very sensible eftect : thus many persons 
who are deeply tinged by bile in their blood, experience 
but few effects that can be imputed to the mixture of 
it with the circulating fluids ; and neither the brain 
nor the heart appear to be much influenced by the 
circumstance. 

Bile is miscible with water and with alcohol, and 
also with oily substances ; and it often assumes a green 
colour, when mixed with acids. The colour of the al- 
vine discharges is derived from the bile, and they are 
therefore sometimes very green, when the acetous fer- 
mentation takes place in the contents of the stomach 
and bowels. 

It is asserted by some chemists, that ten parts in 
eleven of the human bile consist of water ; that albu- 
minous matter composes about one forty-sixth part of 
it; and that there is nearly an equal quantity of re- 
sinous matter in it. There is also a small quantity 
(one part in 244) of uncombined soda dissolved in it, 
and a smaller quantity of neutral salts, consisting of 
soda combined with the phosphoric, sulphuric and mu- 
riatic acids. In addition to these there is a very small 
quantity of phosphate of lime and of oxide of iron, 
and some yellow insoluble matter. 

The bile in the Gall Bladder is generally more vis- 
cid than that which is found in the Hepatic Duct, 

SECTION II, 

Of the Pancreas. 

The pancreas is a glandular body^ which has a 
g^trong resemblance to the salivary glands in seve- 
ral particulars. It is seven inches in length, and 
is irregularly oblong in its form, one extremity 
being much larger than the other. Its large extre- 
mity is in contact with the duodenum, and it ex- 
tends from this intestine in a transverse direction to 
the spleen, to which it is connected by the omentum 
and by blood vessels. It is not invested by the 
peritoneum^ but is situated in the space which exists 



The Pancreas. 143 

between the two laminae of the mesocolon, as they 
proceed from the back of the abdomen, before they 
come in contact with each other. It is anterior to 
the aorta and vena cava, and to the mesenteric vein, 
or main branch of the vena portarum ; being con- 
nected to these parts by cellular membrane. At 
ihe right extremity, which is connected with the 
duodenum, is a process of the gland that extends 
downwards in close contact with the intestine. — 
This is called the head of the pancreas, or the lesser 
pancreas. 

The position of the pancreas is such, that one of 
its surfaces looks forwards and rather upwards, and 
the other backwards and downwards ; one edge is 
of course posterior and superior, and the other ante- 
rior and inferior. The posterior of these edges is 
mych thicker than the other, and has a groove or 
excavation which is occupied by the splenic blood 
vessels. 

This gland differs from the other large glands of 
the abdomen, inasmuch as it has not a large artery 
particularly appropriated to it ; but instead of this, 
it receives branches from the contiguous arteries. 

The arterial blood of this gland is partly supplied 
by the splenic artery, which, in its course from the 
main trunk of the coeiiac to the spleen, while it is in 
the groove at the edge of the pancreas, sends off int(i 
the gland one considerable branch called the great 
pancreatic, and a number of small branches, which 
go off in succession. In addition to these, the pan- 
creas receives vessels from one of the branches of 
the hepatic artery, before it sends off its great rami- 
fications, as well as small twigs from several other 
contiguous arteries. The veins correspond with the 
arteries, but ultimately are discharged into the vena 
porta rum. 

The pancreas resembles t!ie salivary glands ic 



144 Pancreatic Duct, 

colour, and also in texture ; foj: it is of a dull white 
colour with a tinge of red, and it appears to consist 
of small bodies of a granulated form, which are so 
arranged as to compose small masses or lobes that 
are united to each other by cellular membrane. — 
Each of these granulated bodies receives one or 
more small arterial twigs, and from it proceeds not 
only a vein but a small excretory duct, which, 
uniting with similar ducts from the adjoining granu- 
lated portions or acini, forms a larger duct in each 
lobe or mass ; these open into the great duct of the 
gland, which proceeds through it lengthwise from 
the left extremity, iu which it commences, to the 
right. 

This duct is situated in the body of the gland, 
which must be dissected to bring it into view. It is 
thin and transparent, like the ducts of the salivary 
glands, and is rather larger in diameter than a crow's 
quill. In its progress towards the right extremity 
of the gland it gradually enlarges, and commonly 
receives a branch from the part called the lesser 
pancreas. It most commonly unites v^^ith the biliary 
duct before it opens into the duodenum : sometimes 
these ducts open separately, but very near to each 
other. They penetrate the coats of the intestine 
rather obliquely, and between four and five inches 
from the pylorus. This canal is sometimes called 
Ductus Wirsungi, after an anatomist who published 
a plate of it. 

The pancreas has an irregular surface, and no 
coat which covers it uniformly. It is invested by 
cellular membrane, which also connects its diJBFerent 
lobes to each other. Absorbent vessels and nerves 
are traced into it. 

The portion called the lesser pancreas adheres to 
the duodenum, and when it is enlarged by disease^ 



Size of the Spleen. 145 

the passage of aliment through that intestine is much 
impoded, and sometimes completely obstructed.* 

It is now generally believed that the fluid secreted 
by the pancreas is similar to that which is produced 
by the salivary glands. 

SECTION III. 

Of the Spleen. 

The Spleen is a flat body of a bluish colour, and 
an irregular oblong form, with thick edges, which 
are indented in some places. 

It is various, in different subjects, both in size 
and form. Its most common size is between four 
and five inclies in length, and about three or four 
inches in breadth ; but it has often been found of 
more than four times this size; and it has also been 
seen not much longer than an inch. Its ordinary 
■weight is between six and nine ounces ; but it has 
varied in different subjects from eleven pounds to one 
ounce. It is supposed, by many physiologists, that 
it frequently varies in size in the same individual. 

It is situated in the left hypoclu)ndriac region, in 
contact with the diaphragm, below the eighth rib. 
The position of the spleen is somewhat oblique,-— 
one extremity being directed downwards and rather 
forwards, and the other upwards and backwards ; 
but when the stomach is distended, the lower end of 
it is pushed forward by the great extremity of that 
viscus. 

In general it is so deeply seated in the left hypo-,y 

I'so 

• In several cases where examination after death evinced that 
^e pancreas had become enlarged and indurated, particularly at 
the rij^ht extremity, the principal symptoms were yaw^irf/cc; great 
uneasiness after taking food ; vomiting so?ne time after eatings 
hut not immediately ; extreme acidity of(fi£ matter rejected. 

Vol. XL 19 



1.46 Enlargement of the Spleen, 

chondriac region, that it is out of view when the sub- 
ject is opened in the ordinary way : but in some 
cases of enlargement, after the intermitting fever, it 
lias extended downwards, nearly as low as the pel- 
vis ; and towards the right side, beyond the umbi- 
licus. 

The external surface of the spleen is convex, in 
conformity to the surface of the diaphragm, with 
"whicli it IS in contact. The internal surface of the 
spleen is irregularly concave, having a longitudinal 
fissure which divides it into two portions. 

The spleen is invested by the peritoneum, one 
process of which is often extended from the dia- 
phragm, above and behind it, in the form of liga- 
ment. Another process of the same membrane is 
extended to it from the great extremity of the sto- 
mach. The peritoneum is also continued from the 
spleen in the form of omentum. 

Within this peritoneal covering is the proper coat 
of the spleen, which is so closely connected to it, 
that many anatomists have considered them as one 
membrane : they are, however, very distinct at the 
great fissure, but the external coat is extremely thin. 

The proper coat of the spleen is not very thick ; 
it is dense and firm, and somewhat elastic, but not 
much so. It is partly transparent. 

The spleen has a large artery, which is one of the 
three great branches of the co&liac. This vessel runs 
in an undulating manner in a groove in the upper 
edge of the pancreas, and in this course sends off 
many small branches to supply that gland. The 
l^jjiplenic artery, before it arrives at the spleen, divides 
into five or six branches;, which are also undulating 
in their progress, and penetrate into the body of the 
viscus at the above-mentioned fissure. These 
branches are distributed to every pgyt of the viscus, 
and ramify minutely. 



Vessels of the Spleen. 147 

From these branches, or from the main trunk be- 
fore it ramifies, three or four smaller branches pro- 
ceed to the left extremity of the stomach. They are 
called vasa brevia or arterisa breves. 

The arteries which enter the spleen are accom- 
panied by veins that emerge from it, and unite to 
form a great trunk. This trunk observes a course 
corresponding to that of the splenic artery, and re- 
ceives veins from the stomach and pancreas, which 
correspond with the arterial branches sent to those 
organs. The splenic vein is one of the principal 
branches of the vena portarura. 

The splenic artery is very large in proportion to 
the viscus to which it is sent, and the vein is unusu- 
ally large in proportion to the artery. The vein is 
also very tender and delicate in its structure. 

The absorbent vessels of the spleen are very nu- 
merous. It has been asserted, that when those of 
the external coat of the spleen are injected, they are 
sufficient to form a fine network on it. The absorb- 
ents of the deep-seated parts unite to the superficial 
at the fissure where the blood vessels enter. They 
terminate in the thoracic duct, after passing through 
several lymphatic glands. 

The nerves of the spleen are derived from the so- 
lar plexus : they form a plexus round the vessels^ 
and accompany them through the viscus. 

The spleen consists of a substance which is much 
softer than that of any other viscus of the abdomen. 
This substance is made up either wholly or in great 
part of the ramifications of the splenic artery and 
vein, which are demonstrated by injections to be very 
minute and numerous in this body. There are also 
many fine white cords, like threads, which pass from 
the internal surface of the inner coat of the spleen 
into its soft substance, in wliich some of them ramify. 
These cords connect the substance of the spleen 



148 Malpighi on the Structure of the iSpke?i. 

pretty firmly to its coat, and they seem to have the 
effect of rendering the exterior part of the substance 
more firm and dense than the internal. They arc 
particularly conspicuous if the spleen be immersed 
in water, and the coat pulled off while it is in that 
situation. 

The spleen has a strong resemblance to the glan- 
dular organs, but has no excretory duct, and its par- 
ticular function is not very obvious : for these reasons 
the structure of this organ is a subject of very inter- 
esting inquiry. 

Malpighi, who took the lead in researches of this 
nature, before injections of the blood vessels with 
wax were in use, after investigating the structure of 
of the spleen by. long maceration, by boiling, by in- 
flation, by the injection of ink or coloured fluids, and 
by examination with microscopes, declared that its 
structure was cellular ; that the cells communicated 
more freely with the veins than the arteries ; and 
that tliey might be considered as appendices of the 
veins. He also asserted, that a large number of 
white bodies or vesicles were to be found in those 
cells, and throughout the whole substance of the 
spleen, which were in bunches like grapes, and pre- 
served their whitish colour although the vessels 
around them were injected with a coloured fluid. 
This description of Malpighi appears to have been 
admitted by some of the very respectable anatomists 
who were cotemporary with him ; but it was most 
zealously opposed by Ruysch, who exhibited the 
spleen so completely injected with wax, that it ap- 
peared to be composed entirely of vessels.* 

Huyscb appears to have paid great attention to 

* Two plates, taken from drawings of these preparations, are 
published in Ruysch's works. One is attached to Epistola Pro- 
blematica Quarta, in the second volume ; and the other to Thesau- 
rus Septimus, in the third volume. 



De La Sone on the Spleen, 149 

'ibis subject, and to have made many preparations of 
thtt spleen. From these he derived the opinion, that 
the substance of this organ was entirely composed of 
arteries, veins, absorbent vessels and nerves ; autl 
that if it were properly injected before it was dis- 
sected, no other structure would be found. He 
stated, that the minute ramifications of the blood 
vessels appeared to have acquired a peculiar quality, 
and were so soft and delicate, that their texture was 
destroyed by the least friction ; and that by the 
slightest degree of putrefaction they appeared to be 
reduced to a fluid state. He also denied the exist- 
ence of cells, or of the whitish bodies described by 
Malpighi. 

The question thus at issue between these great 
masters of their art, was very carefully examined by 
M. De La Sone, a French physician, whose obser- 
vations are published in the Memoirs of the Acade- 
my of Sciences for 1754. After repeating the pro- 
cesses of each of these anatomists, and instituting 
some others in addition, he adopted the opinion that 
there was in the texture of the spleen a pulpy sub- 
stance which was not a mere coagulum, but which^ 
however, could not be injected. 

He derived his opinion from this fact among 
others. After macerating the spleen a considerable 
time, and injecting water into the vessels until it re- 
turned colourless, he injected ink, and confined it 
some time in the vessels by tying them : he then 
allowed the ink to flow out of the vessels, and made 
various sections of the spleen, but no ink appeared 
in the pulpy substance, although it was visible in 
many small vessels which ramified in that substance. 
He observes that this could not have been the case^ 
if the pulpy substance liad been composed entirely 
of vessels, as was supposed by lluvsch. 

He also examined the spleen after it had beer. 



i50 Haller and the French AnatomisU on the Spleen, 

injected with wax, according to the manner (rf 
Kuysch, and believed not only that the pulpy mat- 
ter remained uninjected, but that Ruysch himself, 
in his own preparations, removed this substance, 
supposing it to exist for the mere purpose of con- 
necting the vessels to each other. 

To see the blood vessels in the same state of dis- 
tention in which they were during life, he tied the 
splenic vessels in a living animal, and removed the 
•spleen with the ligatures on the vessels. In this 
situation he boiled it, and then examined the ap- 
pearance of the vessels and the pulpy substance. — 
From these, as well as his other observations, he 
decided, that the pulpy substance did not consist 
entirely of vessels, but was an additional and dif- 
ferent structure. 

He also suggested, that as the brain and the 
muscular fibres were so covered by blood vessels in 
the injected preparations of Ruysch, that they ap- 
peared to be composed entirely of vessels, when in 
fact they consisted of a different substance, so the 
pulpy substance of the spleen was covered or ob- 
scured by the blood vessels which passed through 
it, without constituting its whole substance. 

He confirms the account of Malpighi respecting 
the Whitish Vesicles or Follicles; and states, that 
in a majority of cases they are not to be discovered 
without a particular preparation ; but that they are 
generally made obvious by long maceration of the 
spleen in water. In his opinion they are the most 
essential part of the organ. 

Notwithstanding these investigations of M. He 
La 8one, the question respecting the structure of 
the spleen remains not completely decided even to 
this day. 

Haller, who was perfectly well acquainted with 
the subject, inclined to the opinion of- Ruysch ; 



British Anatomists on the Spleen, 15i 

while Sabatier adopted completely the opinion of 
De La Sane. 

It appears from the statement of Gavard, that 
Desault did not admit the existence of the transpa- 
rent bodies ; although he believed that the piilpy 
substance of the spleen consisted of cells which re- 
sembled those of tlie cavernous bodies of the penis. 

Boyer, whose descriptions of the animal structure 
appear to have been formed with scrupulous exacti- 
tude, admits tiie existence of transparent bodies ; 
sometimes so soiall as to be scarcely visible, and 
sometimes as large as the head of a pin. He ob 
serves, that the best method of examining them is to 
place a very thin slice of the spleen between the eye 
and a strong light, when the transparency of these 
bodies occasions the slice of the spleen to appear as 
if perforated. 

x4.s to the general structure of the pulpy substance, 
he avows himself unable to decide respecting it; but 
observes, that upon examining the cut surface of the 
spleen, you perceive black liquid blood flow from 
the vessels ; if you then scrape this surface, you may 
express easily a species of sanies different from that 
which flows from the vessels, which, after exposure, 
becomes red, and resembles coagulated blood ; whe- 
ther this is contained in the capillary vessels, or in 
the cavities of this organ, he acknowledges himself 
unable to determine. 

Notwithstanding the sentiments of these French 
gentlemen, many of the British Anatomists, who are 
entitled to great attention on account of their skill in 
minute injections, have adopted the ideas of Ruysch. 
Among these are to be mentioned the late Dr. ¥. 
Nicholls, and many of the anatomists of London, as 
well as the second Professor Monro, of Edinburgh, 
There are, however, two remarkable exceptions to 
this account of the British anatomists. The late 



15^ British »Qnatomists on the Splee?!, 

Mr. Falconar, who wrote a dissertation on the situa- 
tion and structure of the spleen, which contains the 
sentiments of the late truly respectable Mr. Hew- 
son,* after stating that the organ was extremely vas- 
cular, so that when injected it appeared like a mere 
congeries of vessels, makes this unequivocal asser- 
tion — that there are innumerable cells dispersed 
throughout the whole substance of it, which are so 
small that they are only to be discovered by the aid 
of a 'microscope ; and are to be seen after steeping a 
thin piece of spleen, the blooil vessels of which have 
been minutely injected, in clear water during a day, 
and changing the water frequently. He also adds, 
that the ultimate branches of the arteries and veins 
form a beautiful network on each cell; and that 
these cells are sufficiently distinguished from the 
irregular interstices of the cellular substance, by 
their round figure and their great regularity. 

Mr. Eveiard Home, in his papers on the struc- 
ture and uses of the spleen, confirms the account of 
the vesicles in this organ ; antj^ adds, that these vesi- 
cles are occasionally seen in a distended and in a 
contracted state. That when distended they are 
twice as large as when contracted, and are distin- 
guishable by the naked eye ; whereas, when con- 
tracted, they require a magnifying glass to be dis- 
tinctly seen. These observations appear to have 
been made upon quadrupeds.* 

Professor Soemmering appears to unite in the ge- 
neral sentiment of the British anatomists, that the 
spleen is simply vascular. He says, that the tuber- 
culi which sometimes appear in it, when examined 
with a magnifying glass appear to be composed en- 
tirely of vessels. 

** See Experimental Inquiries, vol. III. 

t See the London Philosophical Transactions for 1808- 



Questions ?^elatingto the Structure of the Spleen. Ip3 

There are therefore two questions not perfectly 
ilecided respecting the spleen. 

First. Whether its general structure is simply 
vascular, or whether there is any other structure, 
either cellular or more substantial, which composes 
its general bulk. 

Second. Whether the small transparent vesicles, 
originally described by Malpighi, are to be regarded 
as essential parts of the structure of the spleen. 

With respect to the first question, the injections of 
Ruysch, and of the British Anatomists in general, 
and even of Mr. Hewson, as well as of Haller and 
Soemmering, seem to afford positive facts in opposi- 
tion to those of a negative kind adduced by M. I)c 
La Sone, and render it highly probable that the ge- 
neral structure is simply vascular. 

But the second question stands on different 
grounds. The existence of gmall transparent vesi- 
cles, although denied by Ruysch, and neglected by 
the British Anatomists in general, was asserted as a 
positive fact by Malpighi and De La Sone ; and their 
assertions have been confirmed, not only by most of 
the French Anatomists, but also by Hewson and 
and Home among the British. 

The sentiments of physiologists respecting the 
functions of the spleen, are more discordant than 
those of anatomists respecting its structure ; although 
the subject has been considered by many authors of 
great ingenuity.* 

• See M.Lieutaud. Elementa Physiologic. 
Hewsonfs Experimental Inquiries, vol. III. 
Dr. Rush. Medical Museum, vol. Ill, 
Haller. Elementa Physiologia:, torn. vi. pag. 414, 

Vol. U. 20 



CHAPTER IV 



OF THE URINARY OKGANS, AND THE GLANDULAB 

RENALES. 

The uvioary organs consist of the Kidneys, which 
are situated in the lumbar regions ; of the Bladder, 
whicli is in the pelvis ; of the JJrtters, which are 
flexible tubes or canals that pass from the kidneys to 
the bladder; and of the Urethra, or tube through 
which the urine is discharged from thfi bladder. 

These organs have but little connexion with the 
peritoneum. The kidneys are behind it ; and a con> 
siderable quantity of cellular membrane is placed 
between them and it. The ureters are also behind 
it; and but a part of the bladder is invested with it. 

The Glandulse Renales are described with the 
urinary organs, on account of their contiguity to the 
kidneys ; and to avoid a derangement of the natural 
order of description they are considered first. 

The urethra pertains to the organs of generation 
as well as to the urinary organs, and can be des- 
cribed most advantageously with them. 

SECTION I. 

Of the Glandulx Henales, 

These are two small bodies, situated on the psoas 
muscles, one on each side of the spine, behind the pe- 
ritoneum and above the kidney, being in contact 
with its upper and anterior edge. They have an ir- 
regular semilunar figure with three sides, one of 



The Kidneys and Ureters. 16S 

which is accommodated to the convexity of the kid= 
ney. Their colour is commonly a dull yellow. 

The appearance and texture of these bodies have 
some resemblance to those of glands, and hence their 
name, but they have no excretory duct. 

When they are laid open by an incision^ a cavity 
often appears, which is somewliat triangular, and 
from the lower part of it a small thin ridge arises.* 

A small quantity of fluid is generally found in it, 
which has a very dark colour in adults, is yellowish 
in young subjects, and red in infants. 

These bodies have not a single artery appro- 
priated to them, as the spleen has, but receive small 
branches from several contiguous sources ; viz. from 
the arteries of the diaphragm, from the coeliac artery 
or the aorta, and from the arteries of the kidneys. 
There is generally one principal vein, as well as 
some that are smaller, belonging to each of these 
bodies : the large vein on the right side generally 
opens into the vena cava, and on the left into the 
left emulgent vein. 

These bodies were first described by Eustachius, 
and have been regarded with attention by many 
anatomists since that period. They exist in a great 
number of animals ; but their nature and functions 
are altogether unknown. 

SECTION II. 

Of the Kidneys and Ureters. 

The kidneys are two glandular bodies which se- 
crete the urine. They are of a dull red colour, and 
their form has a strong resemblance to that of the 
bean which bears their name. They have a pecu- 

• The cavity in these bodies has soiiietiiTics been sought for in 
-/ain. Haller found it in sixteen cases out of nineteen. 



156 The Kidneys^ 

liar texture, wliicli is uniform, aud not granulated 
or composed of acini ; and they are covered by a thin 
delicate tunic, wliich has no connexion with the pe- 
ritoneum. 

They are situated in the lumbar regions of the ab- 
domen, one on each side of the spine. They are 
opposite to the two last dorsal and the two first 
lumbar vertebrse. They rest principally upon the 
psoas and quadratus lumborum muscles, and their 
position is oblique; the concave edge presenting in- 
wards and forwards, the convex edge backwards^ 
and the upper extremity approaching nearer to the 
spine than the lower. 

The Right Kidney is situated rather lower than 
the left : it is below the posterior part of the right 
lobe of the liver, and behind the duodenum and the 
colon. The Left Kidney is below the spleen, aud 
behind the descending portion of the colon. Each 
of the kidneys is below and very near to one of the 
glandulae renales. 

They are surrounded with a large quantity of lax 
adipose membrane, which in corpulent persons forms 
a very large mass of adeps around them ; while in 
the emaciated they are surrounded with a membrane 
almost free from fat. Each kidney has two broad 
sides, two extremities, and two edges. The side or 
surface which is posterior, when tlie kidney is in its 
natural situation, is rather broader than the other. 
The upper extremity, or portion, is also broader 
and larger than the lower. The edge M'hich is pos- 
terior and external is regularly convex ; the anterior 
(t'dge is concave; but the concave edge, or margin, 
is not very regular. In the middle it is largely in- 
dented ; in this indentation is a deep fissure, which 
separates the two broad surfaces or sides of the 
gland from each other ; and here the breadth of the 
posterior surface is evidently greater than the anterior. 



The Kidneys. 157 

Each of the kidneys receives a large artery, whicli 
proceeds immediately from the aorta, nearly in a 
rectangular direction. A vein, which opens into the 
vena cava, accompanies the artery. It is obvious, from 
the situation of the kidneys with respect to the great 
vessels, that the artery on the riglit side must be 
longer than that on the left, and that the reverse of 
this must be the case with the veins ; the veins arc 
also anterior to the arteries. At tlie great fissure 
these vessels divide into several branches, which 
enter the kidney at that place. The branches of 
the vein aie before and above ; those of the artery 
are below, and in the middle. Surrounded more or 
less by the branches of those vessels, is a membra- 
nous sac, the breadth of which extends from above 
downwards. This sac terminates in a tube that 
()roceeds from the lower part of the fissure down to 
the bladder. Tiie sac is denominated the pelvis of 
the kidney, and the tube a ureter: each of these 
parts will soon be ra9re particularly described. 

The substance of the Idduey, as has been already 
said, is uniform in its texture, and of a reddish brown 
colour. When it is divided by an incision made length- 
ways, and from its convex to its concave edge, there 
appears to be a small difference in the different parts 
of it. The exterior part, wliich is called cortical, is 
rather more pale in colour and softer in consistence 
than tlie internal part. It varies in thickness, so 
that some writers have described it as equal to two 
lines, and others to one third of the kidney. In a 
majority of subjects it will be found between the two 
statements. 

The interior part is called medullary, or tubular, 
and appears to be composed of very fine tubes. 
These tubes are so arranged, that a number of pa- 
pillai or cones are formed by their convergence, and 
project into the fissure of the kidney. These pa- 



158 ^ The Kidneys. 

plllos have been supposed to consist of a substance 
different from either of the two above uiendoned, 
but they appear to be formed merely by the tubular 
part. 

The arteries, accompanied by corresponding veins, 
and by nerves and absorbent vessels, after ramifying 
in the Ijssure of the kidney, proceed into its sub- 
stance, and coutiinie their aborescent ramifications 
until they have arrived very near the exterior surface. 
They are so uniformly distributed to the different 
parts of the organ, that when the blood vessels are 
injected with wax, and the substance of the kidney 
is removed from the injected matter, as is the case 
in corroded preparations, the injection exhibits ac= 
curately the form of the kidney. 

The la7^ge branches of the blood vessels occupy 
the vacuities between the papillsa in the fissure of 
the kidney. When they penetrate the substance of 
the kidney, they are inclosed by sheaths which are 
derived from the coat of the gland, and are sur- 
rounded by membrane, w^iich frequently contains 
adeps. 

There are commonly ten or twelve papillse in the 
fissure of each kidney, but there are sometimes more 
and sometimes less than this number. These pa- 
pilla are surrounded by a membranous sac of a cor- 
responding form ; the papilla being a cone, and the 
sac resembling the upper part of a funnel. The 
sac is therefore called an infundibulum, or calyx. 
Sometimes there are two papillse in each infundibu- 
lum, and then the form of the sac is not so regular. 
The infundibulum adheres to the base of the pa- 
pilla, but lies loose about the other parts of it. Each 
Infundibulum communicates, at its apex, with the 
pelvis of the kidney. 

The Pelvis, as has been already mentioned, is a 
membranous sac which terminates in the ureter, ex- 



Cortical and Tubular Portions of the Kidney. 159 

terior to the kidney. This sac generally divides 
itself, in the fissure of the kidney, into three large 
irregular branches, each of which very soon termi- 
nates in three or four of the infundibula above de* 
scribed. That portion of the sac which terminates 
in the ureter, is exterior to the kidney. 

When the interior parts of the kidney are. exposed 
to view, by the section above mentioned, after the 
arteries and veins have been minutely injected, the 
cortical part will be found to consist almost entirely 
of the minute ramifications of these vessels. Among 
them are some small bodies, which are dispersed 
through the substance, like berries on a bush : these 
are asserted also to be composed of vessels. 

The tubular part certainly proceeds from this 
vascular corticle substance : for Ruysch, and after 
him several other injectors, have filled these tubes 
with injection thrown into the arteries. 

The tubuli, of which this part is composed, seem 
to arise obscurely from i\tQ cortical part. Tiiey sooii 
assume somewhat of a radiated direction, and are 
finally arranged so as to form the papillse or cones 
above described. v 

On these papillse or cones some of them can be 
traced, uniting with each other, to form larger tubes, 
which terminate on the surfaces of the papillse, iii 
orifices large enough to be seen distinctly. From 
these orifices urine may be forced out, by compres 
sing the papillse. On this account the tubes have 
been called tubuli uriniferi. 

In the foetal state the kidney is formed of a nuui 
ber of distinct lobuli, each of which consists of ;i 
papillse with the cortical matter connected to its 
base. Soon after biith these lobuli coalesce ; and 
in two or three years tlje substance of tiie kidney 
appears uniform, as above describe*!. In some ani- 
mals this lobnlated strnct(u-«». continues during lif<; - 



160 Mervis and Lymphatics. — Coat of the Kidney 

ill them, and also in the foetus, each lobe appears 
like a distinct organ. Although in the adult kidney 
this structure has disappeared, the papillae and the 
tubular part connected Avith them are somewhat de- 
tached from each other, in a manner corresponding 
to their original arrangement. 

The JVe7wes of the Kidneys originate from the 
semilunar ganglion, formerly mentioned. They form 
a plexus round the blood vessels, and go with them 
into the gland. 

The kidneys have internal and external absorbent 
vessels, although the external vessels are very 
small. These absorbents pass through glands in 
the lumbar region to the thoracic duct. 

The proper coat of the kidney is said, by some 
anatomists, to consist of two laminae ; but this can- 
not be shown in comoion cases. It appears simple 
in its structure, and very flexible. It is but slightly 
connected to the glandular substance which it in- 
closes, and may be easily peeled oif. It is reflected 
inwards at the fissure of the kidney, and can be 
traced inwardly to some distance, forming sheaths 
for the vessels. In this internal situation it is very 
thin. 

The Ureters, 

The pelvis of the kidney terminates exteriorly in 
the Ureter, which is a membranous cylindrical tube, 
rather flattened, and between three and five lines in 
diameter, with some variations in this respect. 

The Ureters descend from the pelvis of the kid- 
ney so as to pass obliquely across the psoas muscle 
and the great iliac vessels. They are behind the^ 
peritoneum, but in contact with it. They approach 
the pelvis near the junction of the os ilium with the 
sacrum, and thence descend forwards and inwardsy 
surrounded with loose cellular membrane; to the 



Structure of the Ureters. l6l 

lower part of the bladder, into which they are in- 
serted at its external and posterior part. They first 
penetrate obliquely the muscular coat, and then pro- 
ceed between the muscular aod internal coats, from 
half an inch to an inch, in an oblique direction, from 
without inwards and forwards, when they terminate 
by small orifices in the internal coat, each of which 
is at an equal distance (rather more than an inch) 
from the orifice of the urethra, thus forming a trian- 
gle with it. 

The ureters are said to have three coats. The 
exterior appears to be derived from the cellular sub- 
stance : within it is another, which has been regarded 
very differently by different anatomists ; some consi- 
dering it as merely membranous, and others as mus- 
cular. If the ureter be laid open, and the internal 
coat peeled off, the muscular structure of this coat is 
often very perceptible. 

The internal coat is called villous, or mucous, and 
is continued from the internal coat of the bladder. 
Over this coat mucous is constantly spread, which 
defends it from the acrimony of the urine. It is very 
difficult to separate the two last mentioned coats from 
each other. 

The ureters receive blood vessels and nerves from 
those of the neighbouring parts. Their internal coat 
is very vascular, and is also very sensible of irrita- 
tion. The passage of a small urinary calculus can 
be traced from the pelvis of the kidney to the blad- 
der, by the exquisite pain and the spasmodic affec- 
tions which it often excites. 

Vol. II. 31 



163 Hituaiion of the Bladder. 

SECTION 111. 

Of the Urinary Bladder. 

The urinary bladder is a large sac, of a muscular 
and membranous structure, which occupies the an- 
terior part of the cavity of the pelvis, immediately 
within the ossa pubis. 

The size of the bladder is in a continued state of 
variation, according to the quantity of urine secreted. 
When moderately distended, it is of an irregular 
oval form, but rather more flat at its lower extremity 
than above. It varies in form according to the dif- 
ferent circumstances of the pelvis to which it has been 
subjected. 

It is fixed firmly and immoveably to the pelvis, 
immediately within the symphysis pubis ; so that it 
is always to be found there of a larger or smaller 
size. This fixture is produced by the attachment of 
the lower portion or fundus of the bladder to the 
parts beneath it, but principally by the anterior liga- 
ments of the bladder which proceed one on each side 
from the lateral surfaces of the prostate gland, and are 
inserted into the pubis of the corresponding side at 
the lower part of the symphysis. These ligaments 
are in fact the extension of a membrane (called by 
the French Anatotiusts,the pelvic aponeurosis) which 
proceeds from the upper part of the pelvis to the 
side of the prostate gland and bladder, and which 
may be seen by turning off the peritoneum from the 
levator ani muscle.^ It is sometimes completely 
empty, and occupies no more space than the thickness 



* See Thesis on Femoral Hernia, 8cc. by Gilbert Breschet. Pa- 
ris, April, 1819. Colles' Surgical Anatomy, Dublin, 1811, for a 
more minute account of this membrane. Ed. 



Situation of the Bladder, l63 

of its coats requires. When moderately distended, 
it occupies a considerable portion of the pelvis : 
Tvhen distention increases, it presses the parts poste- 
rior to it against the sacrum, and extends itself above 
the brim of the pelvis into the general cavity, rising 
not only to the umbilicus, but in some cases to the 
epigastric region. 

In males the relative situation of the bladder and 
rectum is such, that the upper and middle part of 
the rectum is behind the bladder; but the lower part 
of tlie rectum, following the curve of the os sacrum 
and coccygis, is below the posterior part of the blad- 
der. 

In females the vagina and uterus are situated be- 
tween the bladder and rectum ; so that the connexion 
of these last mentioned parts is very different in the 
two sexes. 

The peritoneum is reflected at the anterior part of 
the brim of the pelvis from the abdominal muscles, 
which it lines, to the upper part of the bladder, 
which is generally contiguous to the brim of the pel- 
vis. It continues over to the posterior side of the 
bladder, and passes down upon it some distance to- 
wards the lower part ; but before it has arrived at 
the bottom, it is reflected towards the sacrum. 

In males it extends from the bladder to the rec- 
tum, and in females to the vagina and uterus ; so 
that there is a considerable portion of the lower part 
of the bladder which is not invested by the perito- 
neum. It also follows that when the bladder is ex- 
tended into the abdomen, and rises above the brim 
of the pelvis, that part of it which presents anterior- 
ly, and is in contact with the abdominal muscles, is 
without a covering of peritoneum, being below it. 

The bladder is composed of a coat consisting of 
muscular fibres, of a stratum of cellular substance 
immediately within this, and of an internal lining 



164 Muscular Coat of the Bladder. 

membrane, which has been called villous, but, as 
there are no villi perceptible on it, may be more 
properly denominated mucous. 

It should be observed, that, in addition to these 
coats, the bladder has a peculiar investment of the 
peritoneum, as has been already described ; and 
also of the common cellular membrane, which is 
placed between it and every part to which it is con- 
tiguous. 

The Muscular Coat of the Bladder consists of 
fibres which are not spread over it of a uniform 
thickness, but are thin in some places, and in others 
are collected in fasciculi. They run in every direc- 
tion : some appear longitudinal, others circular, and 
some oblique ; and there are interstices between them 
which are occupied by cellular membrane. The 
longitudinal fibres originate from the lower part of 
the bladder ; and as this is the fixed part of that 
viscus, it is the place from which these fibres must 
necessarily act. These fibres are generally exte- 
rior. There is no arrangement of muscular fibres to 
which the term of sphincter can properly be applied; 
but many anatomists have thought that the fibres 
near the neck of the bladder, by their separate con- 
traction, might prevent the escape of urine ; this 
sentiment, however, is contrary to that of several 
very respectable writers. 

The direction of the fibres, taken collectively, is 
such, that, when they all contract, the cavity of the 
bladder is completely obliterated. 

The cellular substance between the muscular and 
internal coats is dense. It yields in a remarkable 
manner to distention, and recovers its original dimen- 
sions very easily. From its analogy to a similar 
coat in the intestines, it is called the JVervous Coat. 

The Internal Coat of the bladder is of a light co- 
lour in the dead subject, when it has been free from 



Internal Coat of the Bladder, 165 

disease. It has been called villous improperly ; for 
the villous structure is not apparent upon its surface. 
Being continued from the integuments of the body 
which are extended along the urethra, it has been 
inferred, that the surface of this coat was formed by 
the epidermis ; and some respectable authors have 
supposed that they had seen cases in which portions 
of the epidermis of the bladder had separated and 
been discharged ; but these appearances are very 
equivocal; and it is by no means certain that an 
epidermis exists there.* 

The fasciculi of fibres of the muscular coat occa- 
sion this coat to appear very irregular, but these 
irregularities correspond exactly with the arrange- 
ment of the fibres of the muscular coat. 

When the internal coat is separated by dissection 
from the muscular, its surface is very smooth and 
uniform. In the recent subject, when no disease 
has previously existed, it is always spread over with 
mucous of a light colour, but nearly transparent, 
which can be easily scraped off. This mucous is 
spread upon the surface so uniformly, that it must 
be derived from sources which are situated upon 
every part of the surface ; but these sources are not 
very obvious. On the membrane of the nose the 
orifices of many mucous ducts are very visible, but 
such orifices are not to be seen on this surface. — 
Haller mentions that he has seen mucous glands 
near the neck of the bladder ; and it is stated by the 
pupils of Desault, that, in one of his courses, lie 
pointed out a number of these glands, in a subject 
who had been afflicted with a catarrhal aflfection of 
the l)ladder. 

• In the fauces and tUe follicles of the tonsils an effusion of coagu- 
lablc matter, in consequence of inflammation, often forms crusts, 
th-Jt may be mistaken for sloughs of the integuments, although 
those integuments remain entire. 



166 Mucous of the Bladder. 

Notwitlistanding that the sources of this mucous 
are obscure, the quantity of it is sometimes immense. 
In some cases^ where the secretion is increased by 
the irritation of a calculus in the bladder, the urine 
is rendered somewhat viscid and white coloured by 
the mucous mixed with it ; which, after the urine has 
been allowed to remain for some time, subsides in 
such quantities as demonstrates that many ounces 
must be secreted in the course of the twenty-four 
liours. The same circumstances occur, without the 
irritation of calculus, in the disease called catarrhus 
vesicse..* 

It is probable that, in healthy persons, a great deal 
of it passes off unperceived, being dissolved or dif- 
fused in the urine. From the quantity and the regu- 
lar diffusion of this mucous on the surface of the 
bladder, there is the greatest reason for believing 
that it is effused from every part of the surface ; and 
it is a question that has not been decided whether it 
is discharged from glandular ducts too small to be 
perceived, or from the exhalent extremities of the 
blood vessels. It is probable that the use of it is to 
defend the internal coat of the bladder from the acri- 
mony of the urine. 

The symptoms of a stone in the bladder, as well 
as of several other diseases, evince that this coat is 
endued with a great degree of sensibility. 

It is evident that the essential parts in the general 
structure of the bladder are the muscular coat and 
the internal coat last described : but in addition to 
the account of them, there are some other important 
circumstances to be noted in the description of this 
organ. It has been already stated, that the form of 
the bladder was an irregular oval, although it was 

* In some cases this mucous soon becomes putrid, and during the 
putrefactive process deposits a substance "which appears to be cal- 



Orifice of the Urethra, 167 

somewhat varied in different persons. The oval form 
is not much altered at the part called the neck of the 
bladder, where the urethra passes off from it. The 
orifice of the urethra is situated anteriorly at the low- 
ermost part of the bladder. On the lower surface of 
the urethra, at its commencement, and on the bottom 
of the bladder, immediately connected with the 
urethra, is situated the Prostate Gland, (to be here- 
after described with the organs of generation,) which 
is a firm body, that adheres strongly both to the 
bladder and urethra. This circumstance gives par- 
ticular firmness and solidity to that part of the blad- 
der. It has also been observed, that the bladder 
is attached firmly to the ossa pubis, at its neck,^ about 
the origin of the urethra. Each of these circum- 
stances have an effect upon the orifice of the urethra: 
and when the bladder is opened, and this orifice is 
examined from within, it appears to be kept open by 
the connexion of the bladder with the prostate and 
has been very justly compared to the opening of the 
neck of a bottle into the great cavity of that vessel.* 
The orifices of the two ureters are at equal dis- 
tances from the orifice of the urethra, and form with 
it the angles of a triangle. That part of the internal 
surface of the bladder which is within this triangu- 
lar space, is more smooth than the remainder of the 
same surface, probably in consequence of the adhe- 
sion of the bladder to the prostate^, and to other parts 
exterior to it. 



* The late Mr. Lieutaud, and after him the French anatomists 
of the present day, liave desmbed a small tubercle at the lower 
and posterior part of the orifice of the urethra, which resembles the 
uvula in form. It has not been noticed here ; and M. Boyer states, 
that it is often scarcely perceptible; He, however, makes a re- 
mark which is very worthy of attention, viz. that it is very subject 
to enlargement in old people, forming a tumour which impedes the 
discharge of urine, Sabatier has also raude the same observation. 



168 Ligaments and Vessels of the Bladder. 

That part of the bottom of the bladder which is 
immediately behind the triangular space, is rather 
lower than this space ; and but a small portion of 
cellular membrane exists between it and the rectum 
in males, and the vagina in females. 

The upper part of the bladder is connected witli 
the umbilicus b^'^ means of a ligament, which passes 
between the peritoneum and the abdominal muscles. 
This ligament consists of three cords. One of these, 
which is in the middle, arises from the coats of the 
bladder, and was, in the foetus, the duct called ura- 
chus ; the other two, which are connected to the 
bladder principally by cellular membrane, were ori- 
ginally the umbilical arteries.* The middle cord 
is of a light colour and fibrous structure ; it is thickest 
at the bladder, and gradually diminishes as it ap- 
proaches the umbilicus. In a few instances it has 
been found to be hollow. In its progress to the 
umbilicus it becomes more or less blended with the 
linea alba, or the tendons of the abdominal muscles. 
The other cords are generally solid. After passing 
from the umbilicus to the bladder, they continue on 
the sides of that viscus, and finally terminate at the 
hypogastric or internal iliac artery. 

In the very young subject these cords are invested 
by distinct processes of the peritoneum, but their 
position is exterior to the peritoneum. 

As the bladder is situated very near most of the 
large ramifications of the hypogastric artery in the 
pelvis, it receives branches from several of them ; 
viz. from the umbilical arteries before they termi- 
nate; from the pubic; from the obturators, &c. These 
branches ramify in the cellular membrane exterior 
to the muscular coat, and also in the cellular sub- 
stance between the muscular and internal coats. It 

* See the accounts of these parts in the description of the Abdo- 
men of the Fcetus. 



General Observation&. 1^ 

has been conjectured, that their terminations in ex- 
halents on the surface of the bladder are remarkably 
numerous. 

The veins correspond with the arteries, but they 
are very numerous on the lower and lateral parts of 
the bladder, and by uniting with the veins of tlie 
rectum form a remarkable plexus. 

The Lymphatic Vessels of this organ do not ap- 
pear more numerous than those of other parts. They 
pass on each side the bladder in the course of its 
blood vessels, and unite with the larger lymphatics^ 
and the glands which lie upon the great blood ves- 
sels on the sides of the pelvis. 

The JSTerves of the bladder are derived both from 
the intercostal nerve and from the nerves of the me- 
dulla spinalis, which pass off through the sacrum ; 
and therefore the bladder is more affected than the 
viscera of the abdomen, by injuries of the medulla 
spinalis. 

The action of the muscular fibres of the bladder in ex- 
pelling urine, and the effect of those fibres which are 
situated near the orifice of the urethra in retaining it, 
can be considered with more advantage after the struc- 
ture of the urethra and the muscles connected witt^ 
that canal have been described. 

It has been stated, that the internal coat of the 
bladder is very sensible ; but it may be added, that in 
consequence of disease about the neck of the bladder, 
the natural sensibility appears most inordinately in- 
creased. When the intensity of pain which accompa- 
nies these complaints, the frequent recurrence of pa- 
roxysms, and their duration, are taken into view, there 
seems reason to believe that none of the painful af« 
fections of the human race exceed those which arise 
from certain diseases of the bladder. Happily these 
diseases are not very common. 

The function of the kidneys is to secrete urine, and 
that of the bladder to retain it until the proper time 
for evacuation. 
Vol. II. 22 



lyo Genm^al Observations. 

The urine may be regarded as an excrementitious 
fluid, which contains many substances in solution that 
are constantly found in it, and many others that are 
occasionally in it, which are taken as aliment or me- 
dicine, and pass to the bladder with little, if any, 
change. The odour of the rose leaf, the colour of 
rhubarb, &c. are occasionally perceived in urine. 

The substances constantly found in urine are nu- 
merous. The chemical account of the subject is so 
long, that it cannot be detailed here ; but the student 
ought to make himself acquainted with it, and he will 
read with great advantage Johnson's History of Ani- 
mal Chemistry, vol. 2d, page 363 ; and also Thomp> 
son's Elements of Chen^istry, page 333. 



CHAPTER T. 

OP THE MALE ORGANS OF GENERATION. 

These organs consist, 1st, of the Testicles, and 
their appendages. 

2d. Of certain parts denominated the Vesiculee 
Seminales and the Prostate Gland^ which are si- 
tuated near the commencement of the urethra, and 
are subservient to the purposes of generation. 

3d. Of the Penis. 

section I. 

Of the Testicles and their appendages. 

The Testicles are two bodies of a flattened oval 
form. Each of them has a protuberance on its up- 
per and posterior part called Epididymis, and is 
connected to parts within the cavity of the abdomen 
by a thick cord, which proceeds to it through the ab- 
dominal ring. Each testicle also appears to be con- 
tained in a sac, which is suspended by this cord and 
covered by the common integuments. 

That portion of the common integuments which 
forms the external covering of the testicles, is deno- 
minated 

The Scrotum* 

The skin of the scrotum, although it is very often 
in a state of corrugation, has the same structure with 
that on other parts of the body, except that it is 



172 Structure of the Scrotum. 

rather thinner and more delicate. The superior de- 
licacy of this portion of the skin is evinced by the 
great irritation produced by the application of sti- 
mulating substances;, and the desquamation of the 
cuticle, which seems to be the effect of irritation. 
There are many sebaceous follicles in this portion 
of skin ; and after puberty there are often a few 
long hairs growing out of it, the bulbs of which are 
often very conspicuous. There is a small raised line 
in the middle oif this skin, which commences at the 
root of the penis, and proceeds backwards, dividing it 
into two equal parts : this line is denominated Raphe, 

The corrugation which so often takes place in the 
skin of the scrotum, appears to be occasioned by the 
contraction of certain fibres, which are in the cellu- 
lar substance immediately within it. This cellular 
substance appears to be attached in a particular way 
to the skin ; and it also invests each testicle in such 
a manner, that when they are withdrawn a cavity is 
left in it. It has long been observed, thr.t no adipose 
matter is found in this cellular substance; but it is 
often distended with water in hydropic diseases. 
As the contraction and corrugation of the scrotum 
has been imputed to this substance, it has been ex' 
amined with particular attention by anatomists, and 
very different sentiments have been entertained re- 
specting it. While some dissectors have asserted 
that muscular fibres could be seen in it, which they 
have denominated the Dartos Muscle ; others have 
said that this substance Mas simply cellular, and 
without any muscular fibres. This difference of sen- 
timent may possibly have arisen from the different 
conditions of this part in different subjects ; for in 
some cases there are appearances which seem to jus- 
tify the assertion that muscular fibres exist in this 
atructure. 

After the testicles are removed, so as to leave the 



Jiction of the Dartos Muscle, 173 

cellular substance connected with the skin, if tlie 
scrotum be inverted, and this substance examined 
in a strong light, many fibres will appear superad- 
ded to the common cellular structure ; and sometimes 
their colour can be distinguished to be red. It is 
not asserted that this will be uniformly the case ; 
but certainly it has often been observed in this way. 

The existence of an organ which possesses the 
power of contraction, within the skin of the scrotum 
and connected to it, is evinced by the corrugation 
which takes place when the scrotum is suddenly ex- 
posed to cold, after having been very warm. This 
corrugation occurs in a very sudden and rapid man- 
ner, in some cases, in which the wounded scrotum 
is thus exposed for the purpose of dressing : foi' 
example, upon removing an emollient poultice from 
this part some days after the operation for the cure of 
hydrops testis, by incision, if the air of the chamber 
be cool, a motion of the scrotum will take place, 
almost equal to the peristaltic movements of the in- 
testines. 

The Arteries of the scrotum are derived from two 
sources. One or two small arteries, which arise from 
the femoral artery, between Poupart's ligament and 
the origin of the profunda, are spent upon it. These 
are called the external pudic arteries. It also re- 
ceives some small branches from the internal pudic 
artery. 

The J^erves of the scrotum are principally derived 
from the lumbar nerves. 

The Spermatic Cord. 

The cord which proceeds to the testicle through 
the abdominal ring, appears at first view like a bun- 
dle of muscular fibres ; but it consists of an artery 
and veins, with many lymphatic vessels and nerves, 
and also the excretory duct of the testicle, connected 



174 Cremaster Muscle. — Bloodvessels of the Testide. 

to each other hy cellular substance, and covered by 
an expansion of muscular fibres which are derived 
from the lower edge of the internal oblique muscle 
of the abdomen, and continue from it to the upper 
part of the testicle. These fibres constitute the 
Cremaster Muscle. 

The artery above mentioned is called the Sperma- 
tic. It commonly arises from the front of the aorta, 
very near its fellow, at a small distance below the 
emulgents : and is not much larger than a crow's? 
quill. It proceeds downwards behind the perito- 
neum and before the psoas muscle and ureter.-^ 
While it is in contact with the psoas muscle, it joins 
the ramifications of the vein, [t afterwards meets 
the vas deferens, and proceeds through the abdomi- 
nal ring to the back part of the testis. Before it ar- 
rives at the testis it divides into several branches, 
two of which generally go to the epididymis, and 
the others penetrate the tunica albuginea on the 
upper and back of the testicle, and ramify very 
minutely on the fine membranous partitions which 
exist in that body. 

In addition to the spermatic artery, there is a 
small twig from the umbilical branch of the hypo- 
gastric, which passes to the spermatic cord along 
the vas deferens. 

The branches of the spermatic vein are much 
larger than those of the artery : several of them pro- 
ceed from the testicle so as to correspond with the 
arterial branches ; and in addition to these there are 
many smaller, which also arise from the testicle and 
epididymis. In their course up the cord they rami- 
fy, and again unite, so as to form a considerable 
plexus, which is called the Corpus Pampinifonne^ 
and constitutes a considerable part of the volume of 
the spermatic cord. 

As they proceed upwards they unite into a few 



Lymphatics and J\*erv€S of the Spermatic Cord. iT6 

larger veins ; and finally, on the psoas muscle, they 
generally form one trunk, which continues upwards 
so as to unite with the vena cava on the right side, 
and the emulgent vein on the left. 

Sometimes, but not often, there are several sper- 
matic veins on each side. 

The Lymphatic Vessels of the testicle are very 
numerous, considering the size of the organ. Six 
or eight, and sometimes more, large trunks have 
been injected, running upon the cord, and continuing 
to the glands on the back part of the abdomen. 

The JVerves of the testicle are derived from those 
which supply the viscera of tlie abdomen, and are 
to be found in the cord although they can scarcely 
be traced to the testicle. A small plexus, called 
the spermatic, is formed by fibres from the renal 
plexus and from the sympathetic nerve. These 
fibres accompany the spermatic vessels, and in all 
probability enter the body of the testis and the epi- 
didymis. Tlie spermatic cord and cremaster muscle 
receive filaments from the second lumbar nerve. 

In addition to these vessels, the Vas Deferens^ 
which is much firmer than either of them, is always 
to be distinguished in the back part of the cord. 

They are all covered in front and on the sides by 
the cremaster muscle, which passes with them from 
the lower margin of the internal oblique, through the 
abdominal ring, and continues to the upper part of 
the external coat of the testicle, which is a sac appa- 
rently containing that organ, and upon this sac it is 
spread out and terminates. 

The Tunica Vaginalis^ 

The External Coat of the testicle, which is com- 
monly called the Tunica Vaginalis^ is a complete 
sac which incloses the testicle as the pericardium 
incloses the heart. It covers the body of the testicle 



176 Coats of the Testicle. 

and epididymis, and adheres closely to them. It is 
then reflected from them so as to form a loose sac, 
which appears to contain them. The cavity of the 
tunica vaginalis commonly extends above the body 
of the testis up the cord, and is oval or pyriform. — 
This sac is so reflected from the body of the testicle 
that there is a place on the upper and back part of 
that body at which the blood vessels enter it, with- 
out penetrating the sac. 

It resembles the peritoneum and other serous mem= 
branes in texture, and is therefore thin and delicate. 
It always contains a quantity of moisture, sufficient 
to lubricate the surface which it forms. 

When the tunica vaginalis is laid open, the testi- 
cle appears as if it were contained in the posterior 
part of its cavity. 

The testicles, as has been already stated, are of a 
flattened oval form. Their position is somewhat 
oblique, so that their upper extremities look upwards 
and forwards, their lower extremities downwards 
and backwards, and their edges present forwards 
and backwards. 

The body of the testicle is very firm, in conse- 
quence of its inclosure in a very firm coat called 
Tunica £Ibuginea. Upon the upper and posterior 
part of it is the protuberant substance, called Epididy- 
mis, which is less firm, being exterior to the tunica 
albuginea. The blood vessels of the testicle pass 
into it on the posterior edge, at some distance below 
the upper end. 

The Tunica Albuginea^ 

In which the body of the testicle is completely 
inclosed, is firm and dense ; and upon this coat its 
particular form depends. It is of a whitish colour, 
and has a smooth external surface. It is thick as 
well as strong. The epididymis is exterior to it. 



Form and Connexions of the Epididymis. 177 

It is only perforated by tiie blood vessels, lympha- 
tics and nerves, and by the vasa efferentia, which 
carry out the secretion of the testis. One portion of 
the tnnica vaginalis adheres very closely to it, and 
the other appears to contain it. The portion which 
adheres to it is with difficulty separated, but it is a 
distinct membrane. 

The Epidydimis 

DiiFers in colour from the testicle, being more or 
less reddish. It commences at the upper and ante- 
rior extremity of the testicle, and passes down the 
posterior edge to the lower end. 

At the commencement the epididymis is somewhat 
rounded in form, and its upper part, or head, has 
been called the globus major : as it descends it 
lessens, and about the middle of the testicle it is 
flattish. 

It is firmly attached to the bodj' of the testicle, at 
the upper end, where the vasa efferentia pass to it; 
and it is also attached to it below ; but at the middle 
it appears nearly detached from it. It has therefore 
been compared to an arch resting with its two extre- 
mities on the back of the testis ; it is, however, in 
contact with it at its middle; but about the middle 
it only adheres by one of its edges to the body of 
the testis, and generally by its internal edge. It 
has a coat which is less firm than the tunica albugi- 
iiea of the testicle, described on the last page. The 
tunica vaginalis of the testicle is so reflected as to 
cover a great part of the epidydimis which is not in 
contact with the testicle, and also those surfaces of 
the epidydimis and testis which are in contact with 
each other and do not adhere. 

The Body of the Testicle. 
When the tunica albuginea is cut through, and 
the substance of the testicle examined, it appears 
Vol. II. 23 



178 Tubuliy Septa and Blood vessels of the Testicle. 

to consist of a soft jiulpy sub«tance of convoluted 
threads, of a yellowish brown colour, which is di- 
vided into separate portions by very delicate septa, 
attached to the internal surface of the tunica albugi- 
nea at the posterior part of the testicle. After ma- 
ceration, by using a fine needle to detach them from 
the cellular substance, these threads may be drawn 
out to a great length. In some animals they are 
larger than in the human species ; in tliera, it is said, 
they are evidently hollow, and that very small 
blood vessels appear in their coats. When mercury 
is injected into the vas deferens, or excretory duct 
of the testis, in a retrograde course, it can be per- 
ceived in these ducts in the human subject. 

These delicate septa, or partitions, are united to 
the internal surface of the tunica albuginea at the 
posterior part of the testicle, at which place there is 
a body called Corpus Highmorianum, which has 
been regarded very differently by different anato- 
mists. It is a long whitish substance, which extends 
lengthwise on the posterior part of the testis ; and 
was supposed by Haller to resemble one of the sali- 
vary ducts. It is now, however, generally agreed to 
be of a cellular structure, and to contain and support 
the ducts which pass from the subgtance of the testi- 
cle to the epididymis. 

The blood vessels pass into the body of the testi- 
cle upon these septa, and are continued from them to 
the filaments or tubes of which the body of the testi- 
cle consists. As in some animals blood vessels are 
distinguished on these tubes, there is the greatest 
reason to believe that a direct communication sub- 
sists between them, without the intervention of any 
other structure, no other structure having been dis- 
covered : but at the same time it ought to be observed, 
that these tubes have not yet been injected from the 
blood vessels. Some ingenious anatomists have in= 



Blood vessels and Structure of the Testicle, ^c. 179 

jected the artery going to the testicle so successfully, 
that the iujectiou has passed from it into the veins 
comiug out of the testicle ; but it is not now said by 
any of them, that they have filled the tubes in this 
manner. 

Mercury will pass into these vessels from the ex- 
cretory duct of the testicle ; and by means of an in- 
jection in that way, the structure of the testicle can 
be unravelled. 

This structure is as follows : The cavity formed 
by the tunica albugiuea is divided into a number of 
apartments by the very thin septa, or partitions, 
above mentioned. Fi'om the filamentary or tubular 
matter which fills each of these chambers, proceeds 
a number of small tubes or vessels, which observe a 
straight course; they are therefore called Vasa Recta. 
These vasa recta unite with each other and form a 
network on the back of the testis, within the tunica 
albuginea, which is called JRete Testis. From this 
network otiier vessels, from twelve to eighteen in 
number, denominated Vasa Efferentia, proceed 
through the albuginea to the epididymis. These 
vessels are convoluted in such a manner as to form 
bundles of a conical form, which are called Coni 
Vasculosi. The number of these corresponds with 
the numi)er of the vasa efferentia, and they com- 
pose about one third of the epididymis, viz. all 
the upper part of it. The single tubes which form 
each of these cones, successively unite into one duct, 
which is convoluted so as to form all the remainder 
of the epididymis. The lower part of the epididy- 
mis is turned upwards on the back of the testicle, the 
tube gradually enlarges and is less convoluted, and 
finally becomes straight : it then takes the name of 



180 Course of the Vas Deferens. 

Vas Deferens, and continues on the back of the tes- 
ticle and at the inner side of the epididymis to the 
spermatic cord.* f 

A sniall solitary vessel or duct, has been observed 
by Haller, Monro, and several other anatomists, to 
proceed from the upper part of the epididymis : 
sometimes it unites to the epididymis below, and 
sometimes it proceeds upwards. The nature of this 
vessel has not been ascertained with certainty. 

The Vas JJeferens 

Is a very firm tube about one line in diameter, 
whicli is not perfectly cylindrical exteriorly, although 
tlie cavity formed by it is so. This cavity is so 
small in diameter, that it will only admit a fine 
bristle. The coats of the duct have, of course, a 
considerable thickness. The internal coat forms a 
soft surface, analogous to that of the mucous mem- 
branes : the external is firm, and its texture resem- 
bles that of cartilage. Owing to the small size of 
the cavity, the internal coat has not been separated 
from the external. 

* De Graff appears to ha\'e been the first anatomist who made 
much progress in the successful investigation of the structure of 
the testicle ; and Haller ought to be mentioned next to him, on ac- 
count of the plate exhibiting this structure, and the explanation of 
it, which he published in the Philosophical Transactions of Lon- 
don, for 17'49. This plate has been republished by the second 
Monro, in the Literary and Physical Essays of Edinburgh, and 
also in his Inaugural Thesis. Haller has likewise republished it 
in his Opera Minora. It represents not only the vasa efferentia 
and the cones formed by their convolutions, but also the rete testis 
and the vasa recta. Haller could inject no further than this ; but 
Monro and Hunter soon after succeeded so as to fill a considerable 
portion of the body of the testicle with mercury, injected by the vas 
deferens. 

f In Mr. Charles Bell's Anatomical collection in London, there 
is a preparation by his aissistant, Mr. Shaw, in which the tubuli 
testis are completely injected with quicksilver and unravelled. I 
saw also in Leyden, one nearly as successfully executed by Profcs- 
sor Sandifort.— Ed. 



Course of the Vas Deferens. 181 

It passes upwards in the posterior part of the 
spermatic cord, and continues witli it through the 
abdominal ring, under and exterior to the perito- 
neum ; soon after this it leaves the cord and dips 
down into tiie cavity of the pelvis, forming a curve 
on the side of the bladder, and proceeding back- 
wards, downwards and inwards, in this course it 
crosses the ureter, and passes between it and the 
bladder. On the lower part of the bladder the two 
vasa deferentia approach each other so gradually, 
that they appear to be nearly parallel. They pro- 
ceed forward between the vesiculse seminales, which 
are two bodies irregularly convoluted, that are placed 
in a converging position with respect to each other, 
and communicate with the vasa deferentia. The 
vasa deferentia finally terminate almost in contact 
with each other in the posterior part of the prostate 
gland, where they perforate the urethra. At the 
distance of about two inches and a half from their 
termination they enlarge in diameter, and become 
somewhat convoluted. At the posterior margin of 
the prostate they come in contact with the anterior 
extremities of the vesiculse seminales, and unite 
with them. After this union they diminish in size, 
and become conical ; and passing a short distance 
through the substance of the prostate, during which 
they approach each other more rapidly, they pene- 
trate the urethra, so as to open in it on each side of 
a small tubercle, called the Caput Gallinaginis, 
soon to be described. 

SECTION II. 

Of the Vesiculse Seminales and the Prostate Gland, 

The Vesiculse Seminales are two bodies of a 
whitisli colour, and irregular form, being broad and 
flat at their posterior extremities, and terminating in 



182 Structure of the Veslculse Seminales. 

a point at the other. Their surfaces are so convo- 
luted, that they have been compared to those of the 
brain. They are situated between the rectum and 
bladder, and are connected to each by cellular mem- 
brane. 

When the vesiculse seminales are laid open by an 
incision, they appear to consist of cells of a conside- 
rable size, irregularly arranged ; but when they are 
carefully examined exteriorly, and the cellular mem- 
brane about them is detached and divided, they ap- 
pear to be formed by a tube of rather more than two 
lines diameter, and several inches in length, which 
terminates, like the csecum, in a closed extremity. — 
From this tube proceed from ten to fifteen short 
branches, which are closed in the same manner. — 
All these tubes are convoluted so as to assume the 
form of the vesiculse seminales above described ; and 
they are fixed in this convoluted state by cellular 
membrane, which firmly connects their different 
parts to each other. It is obvious, that tubes thus 
convoluted, when cut into, will exhibit the appear- 
ance of cells, as in the present instance. 

This convoluted tube, composing the vesiculse 
semioales, terminates in a very short duct, which is 
nearly of the same diameter with the vas deferens, 
and this duct joins the vas deferens so as to form an 
acute angle. 

From the union of the vesiculse seminales with the 
vas deferens on each side, a canal, which seems to 
be the continuation of the vas deferens, proceeds 
through part of the prostate to the urethra, which it 
perforates. These canals are from eight to twelve 
lines in length; they are conical in form, their 
largest extremity being equal to the vas deferens at 
that part. 

If air or any other fluid be injected through the 
vas deferens into the urethra, it will pass at the same 



Function of the Vesiculae Seminales. 183 

time into the vesiculse seminales, and distend them. 
It has been observed, that a fluid passes in this man- 
ner much more readily from the vasa defereutia into 
the vesiculsB seminales, than it does from these last 
mentioned organs into the duct. 

These organs were generally regarded as reser- 
voirs of semen, and analogous to the gall bladder in 
their functions, until the late Mr. J. Hunter pub- 
lished his opinion that they were not intended to 
contain semen, but to secrete a peculiar mucous sub- 
servient to the purposes of generation. 

He states the following facts in support of his opi- 
nion. 

A fluid, very different from semen, is found after 
death in the vesiculse seminales. 

In persons who have lost one testicle, a consider- 
able time before death, the vesiculse seminales on 
each side are equally distended with this peculiar 
fluid. In the case of a person who had a deficiency 
of the epididymis on one side and of the vas deferens 
on the other, the vesiculse were filled with their pe- 
culiar fluid ! 

The sensation arising from redundance of the 
secretion of the testes, is referred to the testes, and 
not to the vesiculse seminales. 

In some animals, there is no connexion between 
the vasa deferentia and the vesiculse seminales. 

See Observations on certain parts of the Animal 
Economy, by John Hunter. 

The Prostate Gland 

Is situated on the under and posterior part of the 
neck of the bladder, so as to surround tlie urethra. 
Its form has some resemblance to that of the ches- 
nut, but it has a notch on the basis like that of the 
figure of the heart on playing cards, and it is much 
larger than the chesnut of this part of America, 



184 Prostate Gland. — The Penis. 

The basis of this body is posterior, ami its apex 
aaterior ; its position is oblique, between the rectum 
and the symphisis pubis. Below there is in some 
cases a small furrow, which, in addition to the notch 
above, gives to the gland an appearance of being 
divided into two lobes. By turning away the vesi- 
culsB seminales and vasa deferentia from the under 
surface of the bladder we bring into view a small 
tubercle at the upper part of the base of the prostate, 
called by Sir Everard Home the tliird lobe. When 
diseased it projects into the cavity of the bladder. 

It adheres to the urethra and neck of the bladder. 
Its consistence is very firm and dense, resembling 
the induration of scirrhus rather more than the ordi- 
nary texture of glands. 

This gland receives small branches from the 
neighbouring blood vessels, and has no artery of 
consideral)le size exclusively appropriated to it. 

As it lies in close contact with the urethra, the 
ducts which pass between it and the urethra are not 
to be seen separate from these bodies ; but ducts can be 
seen in the substance of the gland, vt^hich perforate 
the urethra, and open on the sides of the caput gal- 
linaginis to the number of five or six on each side. 
By pressure a small quantity of a whitish fluid can 
be forced from these orifices, which is rather viscid, 
and coagulable in alcohol. 

The particular use of this fluid is not known. 

SECTION III. 

Of the Pejiis. 

Thk penis, when detached from the bladder, and 
the bones, to which it is connected, and divested of 
the skin which covers it, is an oblong body, which 
is rounded at one extremity and bifurcated at the 
other. 



Penis. 185 

It is composed of three parts, viz. two oblong bo- 
dies, called Corpora Caverriosa, which, at their com- 
jnencement, form the bifurcated portions, and theji 
unite to compose the body of the crsjan ; and a third 
part, of a spongy texture, which is connected to these 
bodies where they unite to each other, on the under 
side, and c.intinues attached to them during the whole 
extent of their union, terminating in an expanded 
head which covers the anterior extremities of the 
corpora cavernosa. The urethra passes from the 
neck of the bladder, on the underside of the penis, 
to its antci'ior extremity, invested by this third body, 
which is therefore called Corpus Spongiosum Ure- 
thrx. 

The two bifurcated extremities are attached each 
of them to one of the crura of the pubis and ischium ; 
and they unite to form the body of the penis imme- 
diately anterior to the symphisis pubis, to which the 
lower part of it is also attached ; so that the penis is 
firmly connected to the middle of the anterior part of 
the pelvis. The urethra proceeds from the neck of 
the bladder, between the crura of the ischium and 
pubis and the crura of the penis, to join the body of 
the penis at its commencement, and near this place 
its connexion with the corpus spongiosum begins ; 
so that there is a small portion of the urethra be- 
tween the neck of the bladder and the commencement 
of the corpus spongiosum, which is not covered by 
the corpus spongiosum. This is called the membra-: 
nous part of the urethra. 

The penis, therefore, consists of two oblong bo- 
dies of a cellular structure, which originate separate- 
ly, but unite together to form it ; and of the uretina, 
which joins these bodies immedately after their 
union, and is invested by a spongy covering, which 
by its expansion forms the anterior extremity not 
only of the urethra but of the whole penis. These 

Vol. II. 24 



186 Corppra^ Cavernosa Penis. 

three bodies, thus arranged and connected, are co- 
vered by cellular membrane and skin in a manner to 
be liereaftev described. 

The Corpora Cavernosa, 

^Vhich compose the body of the penis^, are two ir- 
regular cylinders^ that are formed by a thick dense 
elastic membrane, of a whitish ligamentous appear- 
ance and great tirmness. They are filled with a sub- 
stance of a cellular structure, which is occasionally 
distended with blood. The crura of these cylindri- 
cal bodies, which are attached to the crura of the 
ischium and pubis, are small and pointed at the com- 
mencement, and are united to the periosteum of the 
bones. In their progress upwards they enlarge, and 
at the symphisis of the pubis they unite so as to form 
an oblong bo^ly, which retains the appearance of a 
union of two cylinders applied to each other length- 
ways ; for above there is a superlicial groove passing 
in that direction, which is occupied by a large vein : 
and below there is a much deeper groove, in which 
the urethra is placed. Between these grooves is a 
septum which divides one side of the penis from the 
other. It appears to pioceed from the strong mem- 
brane which forms the penis, and is composed of 
bundles of fibres, which pass from one groove of the 
penis to the other, with many intervals between them, 
througli which blood or injection passes very freely. 
Sometimes these bundles of fibres, with their inter- 
vals, are so regularly arranged, that they have been 
compared to the teeth of a comb. This septum ex- 
tends from the union of the two crura to their termi- 
nation. 

Each of these cylinders is penetrated by the main 
branch of the pudic artery, which is about equal in 
size to a crow's quill. These arteries enter the cor- 
pora cavernosa near their union, and contiaue 



Cells of the Corpora Cavernosa. iSy 

through their whole extent, sending off branches in 
their course ; the turgescence and erection of the 
penis is unquestionably produced by the blood which 
flows through these vessels into th^ js-enis. 

The interior structure of the penis, when examined 
in the recent subject, is of a soft spongy nature, and 
seems stained with blood. If any fluid be injected 
through the arteries this substance appears cellular, 
and may be completely distended by it. When air 
is injected, and the structure becomes dry, the penis 
may be laid open ; the cellular structure then ap- 
pears as if formed by a number of laminas and of 
filaments, which proceed from one part of the inter- 
nal surface of the penis to another, and form irregu- 
lar cells. It has been compared to the lattice- work 
in the interior of bones; and it is suggested by M. 
Roux, that the fibres of which the structure consists 
resemble those of the strong elastic coat of the penis.* 
If these cells are filled with coloured wax, injected 
by the artery, and the animal substance is then de- 
stroyed by placing the preparation in a corroding 
liquor, the wax which remains shows that the mem- 
branes forming the cells are very thin. 

These cells communicate freely with each other; 
and therefore, if a pipe be passed through the strong 
coat of the penis, the whole of them can be filled 
from it by the ordinary process of injection. 



• Mr. Jno. Hunter says on this subject, " That the cells of the 
corpora cavernosa are muscular, although no such appearance is 
to be observed in men : for the penis in erection is not at all times 
equally distended. The penis, in a cold day, is not so large in 
erection as in a warm one ; which probably arises from a kind of 
spasm, that could not act if it were not muscular. 

In the horse, the parts composing the cells of the penis appear 
evidently muscular to the eye, and iu a horse just killed, they coir- 
tract upon being stimulated," — Ed. 



188 Coi-pus Spongiosum^— Bulb t. 

The Urethra 

Is a membranous canal, which extends from the 
neck of the bladder to the orifice at the extremity of 
the penis ; and for a very great part of its leugtli is 
invested by a spongy structure, called the corpus 
spongiosum urethrse. It proceeds from the neck of 
the bladder along the upper part of the prostate ; 
from the prostate it continues between the crura 
of the penis until their junction : it then occu- 
pies the great groove formed by the corpora caver- 
nosa on the lower side of the penis, and continues to 
the orifice above mentioned. At a small distance 
from the prostrate gland the spongy substance which 
invests it commences, and continues to its termination. 
After this spongy substance has arrived at the termina- 
tion of the corpora cavernosa, it expands and forms 
a body of a particular figure which covers the extre- 
mities of the corpora cavernosa, and is denominated 
the Glands Penis. 

The Corpus Spongiosum begins at the distance 
of eight or ten lines from the anterior part of the 
prostate. It is much larger at its commencement 
than at any other part except the glans, and this 
enlarged part is called the Bulb. It surrounds the 
whole of the urethra, and with the exception of the 
bulb and the glans penis, is of a cylindrical figure. 
It is formed by a membrane which has some resem- 
blance to the coat of the penis, but is much thinner, 
and by a peculiar spongy substance, which occu- 
pies the space between the internal surface of this 
membrane and the external surface of the canal of 
the urethra. The membrane and the spongy sub- 
stance, form a coat to the urethra, which, with the 
exception of the enlargement before mentioned, is 
about one line thick. After this spongy substance 
has arrived at the termination, its coat adheres 
firmly to the coat of the penis. 



Structure of the Corpus Spo7igioswn. 189 

The Bulb, or first enlargement of the corpus 
spongiosum, is oblong, and rather oval in form ; it 
is marked by a longitudinal depression in the mid- 
dle, which is very superficial. It consists entirely 
of the spongy substance above mentioned. 

The Glans Penis is also composed of the same 
spongy substance, but the coat which covers it is 
more thin and delicate than that of the other parts of 
the urethra. The lower surface of the glans is fitted 
to the extremities of the corpora cavernosa, but it is 
broader than the corpora cavernosa, and therefore 
projects over them on the upper and lateral parts of 
the surface of the penis. The edge of the prominent 
part is regularly rounded, and is denominated the 
Coj'ona Glandis. 

Heveral small arteries pass to this spongy struc- 
ture. The pudic artery, as it passes on each side to 
the corpora cavernosa, sends a branch to the bulb of 
the urethra. The same vessel in the substance of 
the penis, also sends branches to the urethra : and 
the artery on the back of the penis terminates in 
small branches, which penetrate the substance of 
the glans. 

By these vessels blood is carried to the spongy 
substance of the urethra, which is occasionally dis 
tended in the same manner that the cavernous bodies 
of the penis are distended during the erection of that 
organ. But the cellular structure of this organ is 
not so unequivocal as that of the corpora cavernosa; 
for if it be injected with coloured wax, and corroded 
in the usual manner, the injected matter will exhibit 
an appearance which has the strongest resemblance 
to a convoluted vessel, like the vas deferens iu the 
epididymis.* 

* Mr. Hunter says, " that the corpus spon,e;iosum urethi-jc and 
glans penis are not spongy or cellular, but made up of a plexus of 
veins. This structure is discernable in the human subject; but is 
much more distinctly seen in many aninnals,.as the horse, Sec."— Ed. 



190 Internal Surf ace of the Urethra. 

The Canal of the Urethra, 
Which conveys the urine from the bladder, is a 
very important part of the urinary organs. It con- 
sists of a vascular membrane with a smooth surface, 
which is perforated by the orifices of many mucous 
follicles, some of which are of considerable size. It 
is extremely sensible, and has so much power of 
contraction, that some persons have supposed mus- 
cular fibres to exist in its structure. 

It is differently circumstanced in different parts of 
its course. While surrounded with the prostate it 
adheres firmly to that body, seeming to be supported 
by it ; and here its diameter is larger than it is far- 
ther forward. On the lower or posterior side of 
this portion of the urethra, is an oblong eminence, 
called Veriimontanum^ or Caput Gallinaginis, which 
commences at the orifice of the urethra, and conti- 
nues throughout the whole portion that is surrounded 
by the prostate gland, terminating at the point of that 
body. The posterior extremity of this tubercle be- 
gins abruptly, and soon becomes thick and large; 
anteriorly it gradually diminishes to a line, which is 
sometimes perceptible for a considerable distance in 
the urethra, in a straight forward direction. In the 
upper edge or top of this body is a groove, which is 
produced by a mucous follicle ; on the lateral sur- 
faces, anterior to the middle, are the orifices of the 
common ducts of the vesiculse seminales and vasa 
deferentia (see page 182,) which are sufficiently large 
to receive a thick bristle. Near these, on each 
side, are five or six smaller orifices of the excretory 
ducts of the prostate gland. At the distance of an 
inch before the extremity of the bulb of the urethra, 
ill the lining membrane, are the openings of two 
micts, one on each side, that lead to small glandular 
bodies called Cowper's glands, which are situated 
on each side of the urethra below the bulb, but are 
covered by the acceleratores urinse muscles. 



Mucous Ducts of the Urethra. 19 1 

The diameter of the urethra lessens after it leaves 
the prostate. That portion of the canal which is 
between this gland and the bulb, without invest- 
ment, and therefore called the membranous part, is 
the smallest in diameter. 

After it is invested with the spongy substance it 
has a small enlargement, and then continues nearly 
of one size, until it arrives near the glans penis, 
when it again enlai-ges and alters its form, being no 
longer cylindrical but flattened. Its broad surfaces 
Jiave now a lateral aspect. 

From the bulb of the corpus spongiosum to this 
last enlargement, the appearance of the inner surface 
of the urethra is uniform. The membrane is tliin 
and delicate, and in a healthy subject, who has been 
free from disease of these parts, is of a whitish co- 
lour ; but blood vessels are very perceptible in it. 
AVhen it is relaxed, it appears to be thrown into 
longitudinal wrinkles; but it admits of considerable 
extension, being somewhat elastic : when extended, 
its surface appears smooth, as if it were covered 
with an epithelium. Mr. Shaw, of London, has 
described a set of vessels immediately below the in- 
ternal membrane of the urethra, which, when empty, 
are very similar in appearance to muscular fibres. — 
He says he has discovered that these vessels form 
an internal spongy body, which passes down to the 
membranous part of the urethra, and forms even a 
small bulb there. His preparation with a quicksil- 
ver injection of the part is certainly a very satisfac- 
tory proof of its existence.* Throughout the 
whole extent of this part of the urethra, are the 
orifices of a great many mucous ducts or sinuses, 
which pass obliquely backwards. Many of these 
are so small that they cannot be penetrated by 

' See Med. Chirurg. — Transactions of London— vol, 10th. 



1^2 Mucous Ducts of the U?-ethra. 

a bristle, or probe of that size ; but some are larger. 
It has not been observed that any glandular body 
immediately surrounds them^ although they secrete 
the mucous with which the urethra is lubricated. — 
On the lower side of the urethra, near t)ie commence- 
ment of the glans penis, there is one or more of 
them, so large that their orifices sometimes admit 
the point of a small bougie.* 

These organs, when inflamed, secrete the puri- 
form discharge which takes place in gonorrhoea. — 
In a natural state they produce the mucous which is 
constantly spread over the surface of the urethra, to 
defend it from the acrimony of the urine, and which 
passes away with that fluid unperceived. 

The surface of the urethra is endued with great 
sensibility, and is therefore liable to great irritation 
from contact with any rough body or any acrid sub- 
stance. Irritation, thus excited, induces a state of 
contraction, which is particularly remarkable, as no 
muscular fibres are to be seen in its structure. — 
When a bougie has been passed into the urethra for 
a considerable distance, if.it cannot proceed the 
whole way, it sometimes happens that the instru- 
ment will be discharged by a steady uniform mo- 
tion, which seems to proceed from a progressive 
contraction of the urethra, beginning very low down. 
At particular times, after the urethra has been much 
irritated, it will not receive a bougie, although at 
other times a bougie of equal size may be passed to 
the bladder without opposition. This cannot depend 
upon that elasticity which was noticed before.f 

♦They were discovered by Plazzoni, of Padua, in 1621. Their 
number, according to Loder, amounts to about 65— See his plates. 
En. 

f Sir Everard Home, whose professional opinions are of great 
weight, has lately described in the Transactions of the Royal 
Society, the appearance of the lining membrane of the Urethra., 



Co7itractile Power of the Urethra. 193 

Upon the two crura of the peuis, or the beginning 
of the corpora cavernosa, are fixed the muscles called 
Erectores Pe?iis, which are described in the first 
volume.* These muscles cover the crura of the 
penis from their origin to their junction, and not 
only compress them, but also influence the motion of 
the penis when it is distended. 

The bulb of the urethra is covered by a muscular 
coat, called the Accelerator U7'in3e,^ which has the 
effect of driving forwards any fluid contained in the 
cavity of the urethra, and also of giving the same 
direction to the blood in that part of the corpus 
spongiosum. There is also the Transversus Perinei 
on each side, that passes transversely from the tube- 
rosity of the ischium to the bulb of the urethra. — 
Finally the lower part of the sphincter ani muscle, 
which is nearly elliptical in form, is inserted by its 
anterior point into the muscular covering of the bulb 
of the urethra. Upon removing the integuments, 
these muscles are in view ; and the course of the 
urethra from the bladder is concealed, particularly 
by the anterior point of the sphincter ani. When 
the sphincter ani is dissected away from its anterior 
connexions, and the cellular and adipose substance, 
which is sometimes very abundant, is also removed, 
the lower surface of the membranous part of the 
urethra may be brought into view, as it proceeds 
from the prostate gland to the bulb of the corpus 
spongiosum.! 

■when viewed througli a microscope of great powers. From this 
paper it secais that he is fully convinced of its muscular struc- 
ture — Ed. 

• See description of " Muscles about the Male Organs of Gene- 
ration. Vol. I. Part II. Chap. II. 

■j- The natural situation of the membranous part of the urethra, 
and of the prostate gland, as well as their relative position with 
respect to the sphincter ani, rectum, &c. can be best studied by a 

Vol. II. 25 



194 Contractile Power of the Urethra. 

When the accelerator u rinse is removed from the 
bulb of the urethra, there will appear two bodies, 
which have some resemblance to flattened peas. 
They lie one on each side of the urethra, in contact 
or nearly so with its bulb, and from each gland pro- 
ceeds an excretory duct of an inch and a quarter in 
length, between the corpus spons^iosura and the 
lining membrane of the canal of the urethra, and 
opens into the latter. Its orifice is found with some dif- 
ficulty but is large enough to admit a bristle. These 
are Cowper's glands.* 

The penis is connected to the symphisis pubis by 
a ligamentous substance, which proceeds from the 
back or upper surface of the organ to the anterior 
part of the symphisis, and connects these parts firm- 
ly to each other. 

Thus constructed, of the corpora cavernosa and 
the urethra with its corpus spongiosum, and attach- 
ed to the pelvis as above mentioned, the penis is in- 
vested with its integuments in the following man- 
ner.f 

lateral view of the contents of the pelvis ; which is to be obtained 
by removing carefully one of the ossa jnnominata, and dissecting 
the parts which were inclosed by it. 

• These glands were discovered by Mery, in 1684, and described 
by Cowper, in 1699. A third gland, smaller than the preceding, 
connected with the curve of the urethra under the symphisis pubis, 
was discovered by Cowper, and Morgagni speaks of having ob- 
served a fourth. — Ep. 

f There are several fascix and ligaments about the perineum 
which should be connected with the account of its viscera. Im- 
mediately beneath the skin of the perineum is the Perineal Fascia, 
a thin but strong membrane, which extends from bone to bone, oc- 
cupying the space between the anus and the posterior part of the 
scrotum. It is rather better seen in lean subjects than in fat ones, 
for in the latter it is converted in part into adipose membrane. 
When a rupture occurs in the posterior part of the urethra, this 
fascia prevents the urine from showing itself immediately in the pe- 
rineum, and drives it into the cellular structure of the scrotum.^ 

Immediately beneath the perineal fascia are placed the muscles ; 
when they are removed the bulb of the urethra may be seen very 
advantageously, extending in the middle of the perineum almpst to 



Integuments of the Penis. 195 

Integuments of the penis. 

Tlie glans penis, the structure of wliich has been 
already described, is covered by a continuation of 
the skin, wliich appears altered in its texture so as to 
resemble in some respects the skin of the lips, and in 
like manner is covered by a delicate production of 
cuticle. 

Around the corona of the glans, especially on its 
upper part, there are whitish tubercles, which are of 
dift'erent sizes in different persons, but always very 
small. The skin adheres firmly to the whole extent 
of the corona of the glans, and is very delicate in its 
structure as it continues from the glans upon the bo- 
dy of the penis ; but it gradually changes, so as to 
assume the appearance and structure of a common 
skin, and continues in this state over the penis. The 
adhesion of the skin to the ligamentous coat of the 
corpora cavernosa also becomes more loose, owing 
to the quantity and texture of the cellular substance 
whicli connects them. The skin thus connected to 
the penis, has commonly more length than that or- 
gan, even in its extended state. In consequence of 
this greater length, and of its adhering firmly around 
the corona glandis, it necessarily forms a circular 



the anus. It is not loose and pendulous, but is attached by its pel- 
vic surface to the triangular ligament of the urethra. This liga- 
ment is a septum between the perineum and the pelvis, and connects 
itself to the pelvic or internal edges of the rami of the pubis and 
ischii as far down as the origins of the crura penis. It extends from 
the arch of the pubis to the line mentioned, and fills up all the space 
between the bones of the opposite sides. It consists of two lami- 
na, and Cowpci's glands are placed between them. About an inch 
below the symphisis pubis a perforation is made in this ligament 
for the passage of the membranous part of the urethra. 

Just below the symphisis pubis, between the two laminae of the 
triangular ligament, is placed a much stronger ligament, called the 
pubic, which is about half an inch broad, its lower edge is thick and 
rounded. For further detail on the subject of the fascix of the pel- 
vis, see Lessons iii I'ractical Anatomy, by the pK'sent editor. — Ed, 



\ 



196 Integuments of the Penis. 

Md or plait, which varies in size according to the 
length of the skin. This fold is generally situated at 
the comrnencement of the firm attachment of the skin 
to the body of the penis, or around the glans; but it 
may be formed any where upon the body of the penis 
by artificial management. 

This duplicature, or fold of the skin, when it takes 
place so as to cover the glans, is called the Prepuce: 
and the skin which is very tender and delicate for 
some distance from the glans, forms that surface of 
the prepuce which is in contact with the glans when 
it covers that body. 

There is also a small fold of the skin, which is 
longitudinal in its direction, that commences at the 
orifice of the urethra, and extends backwards, on the 
lower surface of the penis. It is unvarying in its 
position, and is called the Frenum. 

It is a general observation, that adeps is not found 
in the cellular substance which connects the skin to 
the body of the penis ; but this cellular substance is 
distended with water in some hydropic cases. 

From the skin immediately below tlie glans, and 
from small follicles on each side of the frenum, is 
secreted an unctuous fluid, which, when allowed to 
continue, becomes inspissated, and acquires a caseous 
consistence and colour, as well as a peculiar odour. 
It sometimes also acquires an acrimony which pro- 
duces inflammation on the surface with which it is 
in contact, as well as the copious secretion of puri- 
form fluid. 

The distribution of the pudic artery in the penis, 
has already been mentioned ; and a further account 
of its origin and progress to its destination, will be 
found in the general account of the arteries. Some- 
times small branches of the external pudic arteries, 
which originate from the femoral, are extended te 
the penis ; and it has been asserted, that branches of 



Blood Vessels and Msorbents of the Penis. 197 

ilie middle hsemorrhoidal artery have also been found 
there, but this does not often occur. 

The Veins of the penis are of two kinds : those 
which originate in the corpora cavernosa, accompany 
the corresponding branches of the pudic artery, but 
communicate more or less with the plexus of veins 
on the lower and lateral part of the bladder. There 
is also a great vein which occupies the groove on 
the back of the penis, between the corpora caver- 
nosa, that appears particularly appropriated to the 
corpus spongiosum urethrae ; for it originates in the 
glans penis, and receives branches from the urethra 
as it proceeds backwards. There are often two of 
these veins, one in the groove and the other more 
superficial : they generally unite near the root of the 
penis. The common trunk then passes between the 
body of the penis and the symphisis pubis, and ter- 
minates in a plexus of veins at the neck of the blad- 
der, which is connected to the plexus above men- 
tioned on the lower and lateral parts of the same 
riscus. 

The Msorbent Vessels of the penis take two differ- 
ent directions on each side. Those which arise from 
the integuments generally, unite so as to form a few 
trunks on the back of the penis, which divide near 
the root of the organ, and proceed to the glands of 
the groin. Those which originate from the interior 
parts of the penis, accompany the blood vessels, and 
terminate in the plexus of lymphatics in the pelvis. 

It ought to be noted, that the superficial lympha- 
tics getierally enter the upper inguinal glands. 

The J^erves of the penis are principally derived 
from the lower sacral nerves, which unite in the 
plexus that forms the great ischiatic. From these 
nerves a branch on each side originates, which passes 
like the pudic artery, between the sacro-sciatic liga- 
ments. In this course it divides into two branches, one 



198 J^Wves. —General Observations. 

of which passes below to the muscles of the penis and 
urethra, and to the contiguous parts ; and some of 
its branches seem finally to terminate in the dartos : 
the other branch proceeds along the crura of the 
pubis and ischium, and passing between the sym- 
phisis pubis and the body of the penis, arrives at the 
upper surface or dorsum of the penis, along which it 
continues on the outside of the veins to the glans, in 
which it terminates. In this course it sends off seve- 
eral branches, some of which terminate in the inte- 
guments of the penis. 

After an examination of the relative situation of the 
muscles and blood vessels of the male organs of gene- 
ration, there appears reason to doubt, whether the 
erection of the penis can be referred to pressure upon 
the veins which return from that organ. Albinus has 
written on this subject. See Acaderaicarum Annota- 
tionum, lib. ii. caput xviii. Haller has also considered 
it, and stated the opinions of several anatomists, in his 
Elementa Physiologise, torn. vii. page 555. 

The manner in which the urine is confined in the blad- 
der does not appear to be clearly understood. The 
connexion of the neck of the bladder with the prostate, 
and the appearance of the contiguous parts of the blad- 
der, do not render it probable that these parts act like 
a sphincter. The late J. Hunter, who paid great at- 
tention to the functions of these organs, was very de- 
cided in his opinion that the contraction of the urethra 
produced the effect of a sphincter of the bladder. He 
has published some very ingenious observations re- 
specting the manner in which urine is discharged from 
the bladder, in his Treatise on the Venereal Disease, 
part III, chapter IX. 

Mr. Hunter also long since asserted, that the vascular 
convoluted appearance of the corpus spongiosum ureth- 
rge was more distinct in the horse than the man. In 
the fifth volume of the Lemons d'Anatomie Comparee 
of Cuvier, the very learned and ingenious author con- 
firms the declaration of Hunter, respecting the vascu- 
lar convolutions of the corpus spongiosum of the horse. 
He states, that the corpora cavernosa of the penis of 
'he elephant appear to be filled in a great degree with 



General Observations. 199 

the ramifications of veins, which communicate with 
each other by such large and frequent anastomoses, 
that they have a cellular appearance. A similar struc- 
ture exists in the horse, camel, bullock, deer, &c. and 
in them all these communicating branches can be dis- 
tinguished from those which extend the whole length 
of the penis. 
The corpus spongiosum urethrse, according to M. Cu- 
vier, is constructed in a similar manner. From these 
facts he is induced to believe that this structure per- 
y^des the whole class of mammalia, 



CHAPTER VI. 

of THE FEMALE ORGANS OF GENERATION. 

The female organs of generation consist of the 
Uterus and Ovaries, with their appendages ; and of 
the Vagina, with the structure which surrounds its 
external orifice. The uterus is situated in the pelvisj 
between the bladder and rectum ; and the ovaries 
are on each side of it. The vagina is a very large 
membranous canal, which passes from the uterus 
downwards and forwards, also between the bladder 
and rectum, and opens externally. 

Connected with the orifice of the vagina are seve- 
ral bodies, which are called the external parts of ge- 
neration, in order to distinguish them from the ute- 
rus and ovaries, and their appendages, and also from 
the canal of the vagina ; which are called the inter- 
nal parts. 

The bladder of urine lies above and in contact 
with the vagina : the urethra is also intimately con- 
nected with it. The description of the bladder and 
urethra is therefore placed at the end of this chapter. 

SECTION I, 

Of the External Parts of Generation. 

The adipose membrane, immediately anterior to 
the syjnphisis pubis, and on each side of it, forms a 
considerable prominence in females, which, at the 
age of puberty, is covered with hair, as in males. 
This prominence is denominated the Mons Veneris. 

Tlie exterior orifice commences immediately be- 
low this. On each side of this orifice is a promi- 



Labia Externa. — Clitoris. SOI 

nence continued from the mons veneris, which is 
largest above, and gradually diminishes as it descends. 
These prominences have some hair upon them. They 
are called the Labia Externa. Their junction be- 
low is denominated the Fourchette. The space 
between the place of their junction and the anus is 
rather more than an inch in extent, and is denomi- 
nated the Perineum. 

As the skin which forms the labia is continued in- 
ternally, it becomes more thin and soft, and is cover- 
ed by a more delicate cuticle. It is also more or less 
florid, and secretes a peculiar mucous. 

In the upper angle, formed by the labia externa^ 
is the upper extremity and glans of the clitoris. 

The Clitoris is a body which has a very strong 
resemblance to the penis, but there is no urethra at- 
tached to it. It has two crura of considerable length, 
which originate, like those of the penis, from the 
crura of the pubis and ischium, and unite at the 
symphisis of the pubis so as to form a body, which 
is not much more than an inch in length, and is 
broad in proportion. The extremity of this organ, 
called the Glans of the Clitojns, forms a small tu- 
bercle, which is covered above and on the sides by a 
small plait or fold of the skin, denominated the Pre- 
puce. These parts are lubricated by a secretion 
similar to that which is observed round the glans 
penis. 

The crura of the clitoris have muscles similar io 
the erectores penis. The interior structure of the 
Clitoris is very similar to that of the corpora caver- 
nosa of tlie penis, or the corpus spongiosum of the 
urethra. It appears constructed for a similar disten- 
tion, an<l is endued with the same sensibility as tlie 
penis. The two lateral parts are also separated from 
each other by a septum, resembling that of the penis. 
It is united to the symphisis pubis by a ligament. 

Vol. II. 36 



SOS Mjmphx. — Hymen, 

The Prepuce of the clitoris has a semicircular 
form : below its extremities two folds or plaits com- 
mence, one on each side, which are situated obliquely 
with respect to each other, so as to form an angle. 
These folds are denominated the JVymphx, 

The JVymphse extend from the clitoris downwards 
nearly as far as the middle of the orifice of the vagina. 
They are situated witljin the external labia, and are 
formed by the skin after it has become more delicate 
in its texture. Their surface however is often some- 
what corrugated. There are many blood vessels in 
their internal structure, and it is supposed they are 
occasionally somewhat tumid. They are flat, and' 
their exterior edge is convex ; so that they are nar- 
row at their extremities, and broad in the middle. 
Their breadth is very variable, and in some instances 
is great. In a majority of cases it is equal to one 
fourth of their length. Their colour in young sub- 
jects is of a bright red; in women advanced in years 
and who have had many children, they are of a brown 
red, and sometimes of a dark colour. 

The use of these parts is not very evident. They 
have been supposed to regulate the course of the 
urine as it flows fiom the urethra, but their efl'ect in 
tWs respect is not great. They have also been sup- 
posed to favour the necessary enlargement of the 
parts in parturition. 

The orifice of the urethra is situated about an 
inch and one quarter further inward than the clito- 
ris. It is often rather less than the diameter of the 
urethra, and is somewhat protuberant. The orifices 
of raucous ducts are to be perceived around it. 

The orifice of the urethra is at the commence- 
ment of the canal of the vagina. Immediately with- 
in this orifice is situated the membrane denominated 
Hymen. 

The Hymen is an incomplete septum^ made by a 



The Vamna, g03 



^& 



fold or duplicature of the membrane which forms 
the surface contiguous to it. Sometimes it is circu- 
lar, with an aperture in the centre. Sometimes it 
has a resemblance to tlie crescent, the aperture be- 
ing at the upper part of it. The hymen has fre- 
quently been found without a perforation, and has 
therefore prevented the discharge of the menstrual 
evacuation. It is generally ruptured in the first in- 
tercourse of the sexes ; and some smalFtubercles, 
which are found on the surface of the vagina near 
the spot where it was situated, are supposed to be 
the remains of it. These tubercles are called Ca- 
rimculse Myrtiformes. 

SECTION II. 

Of the Vag'ma. 

The canal of the vagina, commencing at the hy- 
men and the oriiice of the urethra, is rather more 
narrow at its beginning than it is further inward. 
From this place it extends backwards and upwards, 
and partakes in a small degree of the curve of the 
rectum : while the bladder, which is above it, and 
rests upon it, increases the curvature of the anterior 
part. It is much larger in women who have had 
children than in those who have not. 

The membrane which lines the vagina resembles, 
to a certain degree, the membranes which secrete 
mucous in different parts of the body. Its surface 
appears to consist of very small papillae ; and at the 
anterior extremity of the vagina it forms a great 
number of rugae, which are arranged in a transverse 
direction, botli on the part of the vagina connected 
to the bladder, and on that part which is connected to 
the rectum, while the lateral parts of the vagina are 



204 Corpora Cavernosa. — Sphincter Vaginse, 

smooth. These rugae are most prominent in the mid- 
dle ; so that a raised line appears to pass through 
them at right angles. This line extends from with- 
out inwards. The rugjE on the part next to the blad- 
der are the strongest. 

This arrangement of the surface of the vagina does 
not extend beyond the external half of the canal : 
on the internal half part, or that nearest the uterus, 
the surface is smooth. 

The rugae are considerably diminished in women 
who have had children. 

Throughout this surface are to be seen, in some 
cases with the naked eye, the orifices of mucous fol- 
licles or ducts, which occasionally discharge consi- 
derable quantities of mucous. 

Exterior to this lining membrane of the vagina is 
a dense cellular structure, which has not yet been 
completely investigated : it is of a lightish colour, and 
has some resemblance to the texture of the body of 
the uterus. It is very vascular, and appears to be of 
a fibrous structure. It may be very much distended, 
and seems to have a contractile power. 

At the anterior extremity of the vagina, on each 
side of it, there is, superadded to this, a cellular, or 
vascular substance, from eight lines to an inch in 
breadth ; which, when cut into, resembles the cor- 
pora cavernosa, or the corpus spongiosum of the pe- 
nis. These bodies commence near the body of the 
clitoris, and extend downwards on each side of the 
vagina. They have been called Plexus Retefoi^mis, 
and Corpora Cavernosa Vaginse, and are supposed 
to be occasionally distended with blood, like the cli- 
toris and penis. 

These corpora cavernosa are covered by muscular 
fibres, which pass over them on each side from the 
sphincter ani to the body of the clitoris ; to each of 
which organs they are attached. These fibres con- 



Unimpregnated Uterus. 205 

stitute the sphincter vaginae muscle, and contract the 
diameter of the vagina at the place where they are 
situated. 

The trans vers us perinei muscles also exist in the 
female. They pass from the tuberosities of the ischia, 
and are inserted into a dense whitish substance in 
the perineum, to which the anterior extremity of the 
sphincter ani is likewise attached. 

The vagina is in contact with the rectum behind ; 
the bladder lies upon it and anterior to it. A small 
portion of peritoneum, to be reflected to the rectum, 
is continued from the uterus upon the posterior part 
of it. The lateral portions of it are invested with 
cellular substance. The anterior extremity of the 
uterus, which is called the Os Tinc^e, projects into it 
from above. 

SECTION III. 

Of the Uterus, the Ovaries and their Jlppendages. 
The Uterus 

Has been compared to a pear with a long neck. — 
There is of course a considerable diiference between 
the body and neck ; the first being twice as broad as 
the last. Each of these parts is somewhat flattened. 

In subjects of mature age, who have never been 
pregnant, the whole of the uterus is about two inches 
and a half in length, and more than one inch and a 
half in breadth at the broadest part of the body : it 
is also near an inch in thickness. 

It is generally larger than this in women who 
have lately had children. 

The uterus is situated in the pelvis between the 
bladder and rectum, and is inclosed in a duplicature 
or fold of the peritoneum, which forms a loose septum 
that extends from one side of the pelvis to the other, 
and divides it into an anterior and posterior cham 



206 Ligaments of the Uterus. 

ber. The posterior surface of this septum is opposed 
to the rectum, and the anterior to the bladder. The 
two portions of this septum, which are between the 
uterus and the lateral parts of the pelvis, are called 
the Broad Ligaments. 

On the posterior surface, the Ovaries are situated 
on each side of the uterus, being inclosed by a pro- 
cess of the li£;ament or septum. Above thera, in the 
upper eds^e of the septum, are the Fallopian Tubes, 
which are ducts that commence at the upper part of 
the uterus on each side, and proceed in a lateral 
direction for some distance, when they form an angle 
and incline dovs'nwards to the ovaries. These ducts 
are inclosed between tlie two laminae of the septum 
for the greater part of their length. 

The peritoneum, which forms the septum, is re- 
fleeted from it, posteriorly, to the rectum and the 
posterior surface of the pelvis, and anteriorly, to the 
bladder. In its progress, in each direction, it forms 
small plaits or folds ; two of which extend from the 
uterus to the rectum posteriorly, and two more to the 
bladder anteriorly : these are called the Anterior 
and Posterior Ligaments of the Uterus. 

The other ligaments, which proceed more imme- 
diately from the uterus, are called the Round Liga- 
ments. These arise from each side of the uterus, at 
a small distance before and below the origins of the 
fallopian tubes, and proceed in an oblique course to 
the abdominal rings. These ligaments are also in- 
vested by the peritoneum. They pass through the 
rings and soon terminate. 

In the body of the uterus is a cavity which ap- 
proaches to the triangular form ; and from which a 
canal proceeds through its neck. This cavity is so 
small that its sides are almost in contact, and the 
canal is in proportion ; so that this organ is very 
thick in proportion to its bulk. 



Structure and Cavity of the Uterus. 207 

The substance of wliich the uterus consists is very 
firm and dense: it is of a wliitish colout ,, with a slight 
tinge of red. Inhere are many blood vessels, with 
nerves and absorbent vessels, in its texture. The 
nature and structure of this substance has not yet 
been precisely ascertained. It appears very differ- 
ent indeed from muscle; but the uterus occasionally 
contracts, with great force, daring labour. It is not 
rendered thin by its enlargement during pregnancy, 
and the blood vessels in its texture are greatly en- 
larged at that time. 

Exteriorly, the uterus is covered by the peritone- 
um, as has already been meatioued. Internally it 
IS lined with a delicate membrane tiiat has some re- 
semblance to those which secrete mucous, and is ge- 
nerally of a whitish colour, abounding with small 
orifices that can be seen with a magnifying glass. 
This membrane is so intimately connected to the 
substance of the uterus that some anatomists have 
supposed it was merely the internal surface of that 
substance, but this opinion is now generally aban- 
doned. It is supposed that the colour of this mem- 
brane is more florid about the period of menstruation. 

The cavity of the uterus, as has been observed be- 
fore, is triangular in form. When the organ is in 
its natural position, the upper side of this triangle is 
transverse with respect to the body, and the other 
sides pass downwards and inwards. In each of the 
upper angles are the orifices of the fallopian tubes, 
which are of such size as to admit a hog's bristle. 

The two lower lines of the triangle are slightly 
curved outwards at their upper extremities ; so that 
the upper angles of the triangle project outwards, 
and the orifices of the fallopian tubes are nearer to 
the external surface than they otherwise would be. 

The lower angle of the cavity of the uterus is oc- 
<upied by the orifice of the canal, which passes 



208 Structure and Cavity of the Uterus. 

through the neck of the organ ; this orifice is from 
three to four tines in diameter. The canal is about 
an inch in length, and is rather wider in the middle 
than at either end. On the anterior and posterior 
portions of its surface are many small ridges which 
have an arborescent arrangement, one large ridge 
passing internally from the commencement of the 
canal, from w hich a number of other ridges go off in 
a transverse direction. These ridges extend nearly 
the whole length of the canal. In the grooves, be- 
tween the ridges, are the orifices of many mucous 
ducts. There are also on this surface a number of 
transparent bodies of a round form, equal in bulk to 
a middle sized grain of sand ; the nature and use of 
which is unknown. They have been called Ovula 
JVaboihi, after a physiologist, who published some 
speculations respecting their use, about the com- 
mencement of the last century. 

The canal of the neck of the uterus is very dif- 
ferent from other ducts, for it seems to be a part of 
the cavity to which it leads, and when the cavity of 
the uterus becomes enlarged in the progress of preg- 
nancy, this canal is gradually converted into a part 
of that cavity. 

The lower extremity of the neck of the uterus is 
irregularly convex and tumid. The orifice of the 
canal in it is oval, and so situated that it divides the 
convex surface of the neck into two portions, which 
are called the Lips. The anterior or upper portion 
is thicker than the other. 

This extremity of the uterus protrudes into the 
vagina, and is commonly called Os 2\ncx. As the 
anterior portion or lip is larger and more tumid than 
the pcKsterior, the vagina extends further beyond the 
OS tincse on the posterior part than on the anterior. 



Fallopian Tubes. — Round Ligaments. 209 

The Fallopian Tithes 

Are two canals, from four to five inches in length, 
which proceed between the larainse of the broad liga- 
ments, from the upper angles of the uterus, in a 
transverse direction, to some distance from tlie ute- 
rus, when they form an angle, and take a direction 
downwards towards the ovaries. 

The}^ are formed, for a considerable part of their 
extent, by a substance which resembles that of which 
the uterus consists, and are lined by a membrane 
continued from the internal membrane of the uterus. 
Their extremities appear to be composed of mem- 
brane, which is rendered florid by the blood vessels 
in its texture. At the commencement their diameters 
are extremely small; but they enlarge in their pro- 
gress. This enlargement is gradual for the first half, 
and afterwards sudden; the enlarged part is more 
membranous than the small part, and has a bright 
red colour. The large extremity is loose in the ca- 
vity of the pelvis, and is not invested by the laminae 
of the broad ligaments. Near the termination the 
diameter is often contracted; after which the mem- 
brane which forms the tube expands into an open 
mouth, the margin of which consists of fringed pro- 
cesses : this margin is also oblique, as respects the 
axis of the tube; and the different fringed processes 
are not all of the same length; but the longest are in 
the middle, and the others regularly diminish on 
each side of them : these processes constitute the 
Fmihrise of the fallopian tubes. 

The internal surface of the large extremities of 
these tubes is extremely vascular ; and there are 
9ome longitudinal fibres of a red colour to be seen 
on it. 

The Round Ligaments, 

Which have already been mentioned, are cords of 
Vol. II. 27 



SIO iSh^cture of the Ovaries, 

a fibrous structure, with many blood vessels in them. 
They arise from the uterus below the origin of the 
fallopian tubes, and proceed under the anterior la- 
minsB of the broad ligaments to the abdominal rings, 
through which they pass ; and then the fibres and 
vessels are expanded upon the contiguous cellular 
substance. 

The Ovaries 

Are two bodies of a flattened oval form ; one of 
which is situated on each side of the uterus on the 
posterior surface of the broad ligament, and invested 
completely by a process of the posterior lamina, 
which forms a coat, and also a ligament for it. The 
size of this organ varies in different subjects, but in 
a majority of those who are about the age of matu- 
rity it is between ten and twelve lines in length. It 
is connected to the uterus by a small ligament, or 
bundle of fibres of the same structure with the round 
ligaments, which is not more than two lines in di- 
ameter, and is included between the laminae of the 
broad ligament. 

The process of the broad ligament forms an exter- 
nal coat to the ovary ; within this is the proper coat 
of the organ, which is a firm membrane. This mem- 
brane is so firmly connected to the substance of the 
ovary which it encloses, that it cannot be easily se- 
parated from it. The ovary is of a whitish colour 
and soft texture, and has many blood vessels. In 
virgins of mature age it contains from ten to twenty 
vesicles, formed of a delicate membrane, filled with 
a transparent coagulable fluid. Some of these vesi- 
cles are situated so near to the surface of the ovary 
that they are prominent on its surface; others are 
near the centre. They are very different in size : 
the largest being between two and three lines in 



Arteries of the Uterus. 211 

diameter, and others not more than one third of that 
size. 

In women who have had children, or in whom 
conception has taken place, some of these vesicles 
are removed ; and in their place a cicatrix is found. 

It has been ascertained, that during the sexual 
intercourse with males, one of these vesicles, which 
was protuberant on the surface, is often ruptured, 
and a cavity is found. A cicatrix is soon formed, 
where the membrane was ruptured; and in the place 
occupied by the vesicle there is a yellow substance 
denominated Corpus Luteum. This corpus luteum 
generally continues until the middle of pregnancy : 
it often remains during that state, and for some time 
after delivery, but it gradually vanishes. The cica- 
trization continues during life. 

In many cases these cicatrices correspond with the 
number of conceptions which have taken place ; but 
they often exceed the number of conceptions, and 
they have been found in cases where conception has 
not been known to have taken place. 

In very old subjects, where conception has never 
taken place, the vesicles are either entirely removed, 
or small dense tubercles only remain in their place. 

The Arteries 

Of the uterus are derived from two very diiferent 
sources; viz. from the spermatic and from the hy- 
po,ii;astric arteries. 

The spermatic arteries, instead of passing directly 
down to the abdominal ring, proceed between the 
laminae of the broad ligament, and send branches to 
the ovaries, which may sometimes be traced to the 
vesicles. They also send branches to the fallopian 
tubes and to the uterus. Those which are on the 
opposide sides of the uterus anastomose with each 
other, and also with the branches of the hypogastric 



^IJJ Veins of the Uterm. 

arteries. There are also branches of these arteries 
in the round ligaments, which accompany them to 
their termination outside of the abdominal ring. 

The principal arteries of the uterus are those de- 
rived from the hypogastric, which sends to each side 
of it a considerable branch, called the Uterine. This 
vessel leaves the hypogastric very near the origin of 
the internal pudic, and proceeds to the cervix of the 
uterus : it passes between the laminae of the broad li- 
gaments, and sends branches to the edge of the uterus, 
which penetrate its texture. The branches which are 
in the texture of the uterus are very small indeed, in 
young subjects. In women who have had children 
they are considerably larger ; but during pregnancy 
they gradually enlarge with the growth of the uterus, 
and become very considerable. These arteries ob- 
serve a serpentine and peculiarly tortuous course. 
Those on the opposite sides anastomose with each 
other. 

The Veins 

Of the uterus, like the arteries, form spermatic 
and uterine trunks. The Spermatic Vein is much 
larger than the artery. It ramifies as in males, and 
forms a very large plexus, which constitutes the cor- 
pus pampiniforme. Many of the veins which form 
this body, originate near the ovary : a considerable 
number also come from the fallopian tubes and the 
uterus. The spermatic vein and its branches are 
greatly enlarged indeed during pregnancy ; and it is 
said that they are enlarged the same way during the 
menstrual discharge. 

The most important veins of the uterus are the 
branches of the Uterine Veins. They are extremely 
numerous, and form a plexus on the side of the ute- 
rus ; from which two or more uterine veins proceed 
in the course of the artery, and join the hypogastric. 



Lymphatics. — Bladder and Urethra. 213 

These veins also are greatly enlarged during preg* 
nancy. 

The Lymphatic Vessels 
Of the uterus, and its appendages, are very nil- 
merous. In the unimpregnated state they are small ; 
but, during pregnancy, they increase greatly. They 
proceed from the uterus in very different directions. 
Some that accompany the round ligaments go to the 
lymphatic glands of the groin. Others which take 
the course of the uterine blood vessels pass to glands 
in the pelvis, and a third set follows the spermatic 
arteries and veins to the glands on the loins. 

The JVerves 
Of the ovaries are derived from the renal plexus, 
and those of the uterus and vagina from the hypo- 
gastric plexus, or the lower portions of the sympa- 
thetic, and the third and fourth sacral nerves, 

SECTION III. 

Of the Bladder and Urethra, 

The situation of the Bladder, as respects the sym- 
phisis pubis, is nearly alike in both sexes ; but that 
part of it which is immediately behind the insertion 
of the ureters is rather lower in males than in fe- 
males. The bottom of the bladder rests upon the 
upper part of the vagina, a thin stratum of cellular 
substance only intervening : when that viscus is dis- 
tended it forms a tumour, which compresses the va- 
gina. 

The ureters are inserted, and the urethra com- 
mences in the same part of the bladder, in both 
sexes. 

The length of the Urethra is between one and 
two inches. When the body is in a direct position, 
it is nearly horizontal ; but it is slightly curved, with 



S14 Gradual Change in the Gravid Uterus. 

its convexity downwards. It is immediately above 
the vagina, and it passes below the body of the cli- 
toris. The external orifice of it is rather more than 
an inch within the glans or head of the clitoris. 
This orifice is somewhat prominent in the vagina. 

In the internal or lining membrane of the urethra 
there are many orifices of mucous follicles, and also 
longitudinal wrinkles, as in the urethra of males; 
The diameter of the female urethra and its orifice in 
the bladder are greater than they are in the male. 
For this reason it has been supposed, that women 
are less liable to calculus of the bladder than men.* 

The urethra is intimately connected with the ex- 
ternal coat of the vagina, and between them there is 
a spongy cellular substance which makes the rough 
surface of the vagina prominent ; so that the urethra 
has been supposed, although erroneously, to be in- 
vested with the prostate. It is capable of great ar- 
tificial dilatation. 

Of the Changes induced in the Uterus in the progress 
of Pregnancy. 

The alteration which takes place in the size of the 
uterus during pregnancy is truly great. About the 
conclusion of that period, instead of the small body 
above described, which is almost solid, the uterus 
forms an immense sac, which extends from the ter- 
mination of the vagina in the pelvis, into the epigas- 
tric region ; and from one side of the abdomen to the 
other ; preserving, however, an ovoid figure. 

This change is so gradual at first, that the uterus 
does not extend beyond the cavity of the pelvis be- 
fore the third month, although at the end of the 
seventh month it is very near the epigastric region. 

For the first six months the body of the uterus 

* It has however been asserted that they are also less liable to 
calculi in the kidneys. 



General Observations. 215 

appears principally concerned in the enlargements 
after this the cervix begins to change, and is gra- 
dually altered, so as to compose a portion of the sac, 
rather of less thickness than the rest of the uterus ; 
the mouth being ultimately an aperture in a part 
which is much thinner than the other portions of the 
organ. 

The change which takes place in the texture of 
some of the appendages of the uterus is very impor- 
tant. 

The Broad Ligaments, which seem particularly 
calculated to favour the extension of the uterus, are 
necessarily altered by the change in the size of that 
organ, but not entirely done away. The portion of 
peritoneum of which they are formed must be very 
murh enlarged with the growth of the uterus, as it 
continues to cover it. The Round Ligaments are 
much elongated ; and they observe a more straight 
course to the abdominal ring. The Fallopian Tubes 
are enlarged ; and instead of passing off laterally 
from the uterus, they now proceed downwards by 
the side of it. The Ovaries appear rather larger 
and more spongy : their relative situation is necessa- 
rily lower. 

The change in the Uterus itself is particularly in- 
teresting. The great increase of its size is not at- 
tended with any considerable diminution of thick- 
ness in its substance ; nor are the artei'ies much less 
convoluted than before pregnancy, as might have 
been expected. They are greatly enlarged in diame- 
ter, and the orifices of the exhalent vessels on the 
internal surface of the uterus are much more percep- 
tible. 

The veins are much more enlarged than the arte- 
ries, and in some places appear more than half an 
inch in diameter. They are not regularly cylindri- 



Sl6 Peculiarity of the Female Hottentots. 

cal, but rather flat. They anastomose so as to form 
an irregular net work. 

The uterus appears much more fibrous and mus- 
cular in the gravid than in the unimpregnated state. 
The contractile power of the gravid uterus is not 
only proved by the expulsion of its contents, but 
also by very vigorous contractions, which are occa- 
sionally observed by accoucheurs. 

Although the general eflfects which result from the par- 
ticular conditions of the uterus in pregnancy, men- 
struation, &c. evince that the influence of this organ 
upon the whole system is very great, yet it seems pro- 
bable that the sexual peculiarities of females are espe- 
cially dependent upon the ovaria. 

This sentiment is confirmed by an account of a wo- 
man in whom the ovaria were deficient, which is pub- 
lished in the London Philosophical Transactions for 
1805, by Mr. C. Pears. The subject lived to the age 
of twenty-nine years. She ceased to grow after the 
age of ten years, and therefore was not more than four 
feet six inches in height: her breadth across the hips 
was but nine inches, although the breadth of the 
shoulders was fourteen. Her breasts and nipples never 
enlarged more than they are in the male subject.— 
There was no hair on the pubes, nor were there any 
indications of puberty in mind or body. She never 
menstruated. At the age of twenty-nine she died of 
a complaint in the breast, attended with convulsions. 
The uterus and os tincse were found not increased 
beyond their usual size during infancy. The cavity 
of the uterus was of the common shape, but its coats 
were membranous. The Fallopian Tubes were per- 
vious. " The Ovaria were so indistinct that they rather 
showed the rudiments which ought to have formed 
them, than any part of the natural structure.''^ 

Another case, which confirms the aforesaid sentiment, 
is related in one of the French periodical publica- 
tions. 

It has been long known that a race of savages near 
the Cape of Good Hope were distinguished from the 
generality of their species by a peculiarity about the 
pudendum. An account of this structure has been 



Peculiarities in the Abdomen of the Foetus. %ij 

given with some precision by Messrs. Peron and 
Lesueur, in a paper which was read to the National 
Institute of France. It is a flap or apron, four inches 
in length, which is united to the external labia near 
their upper angle, and hangs down before the clitoris 
and the external orifice of the parts of generation. It 
is divided below into two lobes, which cover the orifice. 
It is formed by a soft distensible skin, free from hair, 
which is occasionally corrugated like the scrotum, 
and is rather more florid than the ordinary cutis.* 

The Abdomen of the Foetus. 

The diflference between the foetus and the adult, 
in the cavity of the abdomen, is very conspicuous at 
the first view. 

The Liver in the fcetus is so large that it occupies 
a very considerable part of the abdomen. Its left 
lobe, which is larger in proportion than the right, 
extends far into the left hypochondriac region. 

The Bladder of urine, when filled, extends from 
the cavity of the pelvis a considerable distance to- 
wards the umbilicus; so that the greatest part of it 
is in the cavity of the abdomen. A ligament of a 
conical figure extends from the centre of the upper 
part of the bladder to the umbilicus ; with an artery 
on each side of it, M'hich is soon to be described. 
This ligament, which is in the situation of the ura- 
chus of the foetus of quadrupeds, is hollow, and thus 
frequently forms a canal, which has a very small 
diameter, that communicates with the bladder by an 
aperture still smaller, and continues a short distance 
from the bladder towards the umbilicus. In a few 
rare instances this canal has extended to the umbili- 
cus, so that urine has been discharged through it, 
but the ligament is commonly solid there. 

* This paper has not yet been published by the Institute, but it is 
referred to by M. Cuvier in his Lecous d'Anatoiuie Compar^c, 
vol. v. page 124. — Messrs. Peron and Lesueur were naturalists 
who accompanied captain Baudin in his vovagc of discovery. 

Vol. II. 28 



218 Descent of the Testicle in the Foetus. 

The Stomach appears to be more curved in the fcE- 
ius than in the adult. 

The Great Intestine does not extend suflSciently far, 
beyond the insertion of the ileon, to form the caecum 
completely. 

The GlandulsG Benales are much larger in pro- 
portion in the foetus than in the adult. The colour 
of the fluid they contain is more florid. 
The Kidneys are lobulated. 

The Testicles in the fcetus are found above the pel- 
vis, in the lumbar region, behind the peritoneum, un- 
til two months before birth. Thus situated, their 
blood vessels and nerves proceed from sources which 
are near them ; but the vas deferens, being connect- 
ed to the vesiculae seminales by one extremity, is ne- 
cessarily in a very diflTerent situation from what it is 
in the adult : it proceeds from the testicle downwards 
to the neck of the bladder. — While each testicle is 
in this situation, it is connected with a substance or 
ligament, called Gubernaculum, of a conical or py- 
ramidical form, attached to its lower end, and extends 
from it to the abdominal ring. This substance is 
vascular, and of a fibrous texture : its large extremi- 
ty adheres to the testicle, its lower and small extremi- 
ty passes through the abdominal ring, and appears 
to terminate in the cellular substance exterior to that 
opening, like the round ligament in females. The 
Gubernaculum, as well as the testicle, is behind the 
peritoneum ; and the peritoneum adheres to each of 
them more firmly than it does to any of the surround- 
ing parts. It seems that, by the contraction of the 
Gubernaculum, the testicle is moved down from its 
original situation to the abdominal ring, and through 
the abdominal ring into the scrotum. The peritone- 
um, which adheres firmly to the gubernaculum and 
testicle, and is loosely connected to the other parts, 
yields to this operation ; and when the testicle has 



Descent of the Testicle in the Pmtus. 219 

arrived near the abdominal ring, a portion of the pe- 
ritoneum is protruded a little way before it into the 
scrotum ; forming a cavity like the finger of a glove. 
The testicle passes down behind this process of the 
peritoneum, and is covered by it as it was in the ab- 
domen. Although it appears protruded into the ca- 
vity, it is exterior to it, and behind it ; and the vessels, 
&c. which belong to the testicle are also exterior 
to it. 

The cavity formed in the scrotum, by this process 
of the peritoneum, necessarily communicates with the 
cavity of the abdomen at its formation ; but very soon 
after the testicle has descended into the scrotum, the 
upper part of this cavity is closed up, while the low- 
er part of the process continues unchanged, and con- 
stitutes the Tunica Vagitialis Testis. In some in- 
stances the upper part of this process does not close 
up, and the communication with the cavity of the 
abdomen continues. The descent of the intestine 
into the cavity thus circumstanced, constitutes that 
species of hernia which is denominated Congenital* 

The most important peculiarities in the abdomen 
of the foetus are those connected with the circulation 
of the blood. 

The internal iliac or hypogastric arteries are larger 

♦ These interesting circumstances respecting the original situa- 
tion of the testicle, and its descent into the scrotum, were discover- 
ed and elucidated by Haller, Hunter, Pott, Champer, and several 
other very respectable anatomists and surgeons. There is however 
a difference of opinion, between some of them, as to the time when 
the testicle leaves the abdomen. Haller thought the testicles were 
seldom in the scrotum at birth. Hunter and Camper found them 
so generally. 

It has been suggested that there are some national peculiarities in 
this respect ; that amongst the Hungarians, for example, the tes- 
ticUs often remain above the abdominal ring until near the age of 
puberty. 

The student will find an interesting description of the situation of 
the testis, and its descent, in the foetus, in the " Observations on 
certain parts of the Anim^al Economv," bv John Hunter. 



220 Umbilical Vessels, 

than the external iliacs. Their main trunks are 
continued on each side of the bladder to its fundus ; 
and proceed from it, with the ligament, to the umbi^ 
licus; when they pass out of the abdomen to go along 
the umbilical cord to the placenta. These arteries 
are now denominated the Umbilical, and are very 
considerable in size. After birth, as there is no cir- 
culation in them, they soon begin to change : the ca- 
vity of them is gradually obliterated, and they are 
converted into ligaments. They are exterior to the 
peritoneum, and contained in a duplicature of it, 

A vein also called the U?nbilical, which is much 
larger in diameter than both of the arteries, returns 
from the placenta along the cord, and enters the ca- 
vity of the abdomen at the umbilicus. It proceeds 
thence, exterior to the peritoneum, but in a duplica- 
ture of it called the Falciform Ligament^ to the 
liver, and enters that viscus at the great fissure; 
along which it passes to the left branch of the sinus 
of the vena portarum, into which it opens and dis- 
charges the blood which ilows through it from the 
placenta. It opens on the anterior side of the branch 
of the vena portarura, and from the posterior side of 
the branch, opposite to this opening, proceeds a duct 
or canal, which opens into the left hepatic vein near 
its junction with the vena cava. This communicating 
vessel is called the Ductus, or Canalis Venosus ; to 
distinguish it from the duct which passes from the 
pulmonary artery to the aorta, and is called Ductus^ 
or Canalis Arteriosus. This venous duct carries 
some of the blood of the umbilical vein directly to 
the vena cava-; but it is much smaller than the um- 
bilical vein, and of course a considerable quantity of 
the blood which passes through the umbilical vein 
must pass through the liver, by the vena portarura, 
before it can enter the cava. 

In some foetal subjects, if a probe of sufficient 



Object of the Circulation in the Placenta. 2%i 

length be introduced within the umbilical vein and 
pushed forwards, it will pass to the heart without 
much difficulty or opposition, as if it proceeded along 
one continued tube, although it really passes from 
the umbilical vein across the branch of the vena por- 
tarum, and then through the ductus veuosus, and 
through a portion of the left hepatic vein, into the 
inferior vena cava. 

If the umbilical vein be injected with a composi- 
tion, which will be firm when cool, it appears to 
terminate in a rounded end, which is situated in the 
transverse fissure of the liver : the sinus of the vena 
portarum, into which this vein enters, appears like 
two branches going off, one from each side of it, and 
the ductus venosus like a branch continuing in the 
direction of the main trunk of the umbilical vein. 

The umbilical vein, in its progress through the 
fissure of the liver, before it arrives at the sinus of 
the vena portarum, sends off a considerable number 
of branches to each of the lobes of that organ, but 
more to the left than to the right lobe. 

After birth, when blood ceases to flow through the 
umbilical vein, it is gradually converted into a liga- 
ment ; and the venous duct is also converted into a 
ligament in the same manner. The vena portarum, 
which before appeared very small, when compared 
with the umbilical vein, now brings all the blood 
which fills its great sinus, and increases considerably 
In size. 

It has been ascertained by anatomical investiga- 
tion, that the umbilical arteries above mentioned, 
after ramifying minutely in the placenta, communi- 
cate with the minute branches of the umbilical vein ; 
and it is probable that the whole blood carried to the 
placenta by these arteries, returns by the umbilical 
vein to the fcetus. 

It is clearly proved by the effects of pressure on 



222 Object of the Circulation in the Placenta, 

the umbilical cord, in cases of delivery by the feet, 
as well as by other similar circumstances, that this^ 
circulation cannot be suspended for any length of 
time without destroying the life of the foetus. From 
these circumstances, and from the florid colour 
which the blood acquires by circulating in the pla- 
centa, it seems probable that the object of the circu- 
lation through that organ is somewhat analogous to 
the object of the pulmonary circulation through the 
lungs of adults,.* 

* During the first four months of pregnancy a very small vesi- 
cle, which does not exceed the size of a pea, is found between the 
chorion and the amnios, near the insertion of the umbilical cord 
into the placenta. It is connected to the foetus by an artery and a 
vein, which pass from the abdomen through the umbilicus, and pro- 
ceeding along the cord to the placenta, continue from it to the ve- 
sicle. The artery arises from the mesenteric, and the vein is united 
to the mesenteric branch of the vena portarum. It is probable that 
these vessels commonly exsist no longer than the vesicle, viz about 
four months ; but they have been seen by Haller and Chaussier at 
the termination of pregnancy. They are called Omfihalo Mesenteric 
vessels. The vesicle is denominated the Umbilical Vesicle. 

This inexplicable structure is delineated in Hunter's Anatomy 
-of the Gravid Uterus, plate xxxiii. figures v. and vi. ; in the Aca- 
demical Annotations of Albinus, first book, plate i. figure xii. ; 
and also in the Icones Embiyonum Humanorum of Soemmering, 
, figure ii. 



SYSTEM OF ANATOMY. 

PAKT IX. 



OF THE BLOOD VESSELS. 

The blood vessels are flexible tubes, of a peculiar 
texture, through which blood passes from the heart 
to the different parts of the body, and returns again 
from these parts to the heart. They are to be found, 
in varying proportions, in almost every part of the 
body, and seem to enter into its texture. 

The tubes which carry blood from the heart, are 
more substantial and more elastic than those through 
which it returns to the heart. They are generally 
found empty after death ; and, therefore, were called 
Arteries by the ancient anatomists, who supposed 
that they carried air, and not blood. 

The tubes which return the blood to the heart are 
denominated Veins. They are less substantial and 
less elastic than arteries, and are generally full of 
blood in the dead subject. 

There are two great arteries, from which all the 
other arterial vessels of the body are derived. They 
are very justly compared to the trunks of trees, and 
the smaller vessels to their branches. One of these 
great arteries, called the Aorta, carries blood to every 
part of the body. The other great vessel, called the 
Pulmonary Artery^ carries blood exclusively to the 
lungs. 



224 The Blood vessels in general. 

The veins which correspond to the branches of 
the Aorta, unite to each other, so as to form two 
great trunks that proceed to the heart. One of these 
trunks, coming from the superior parts of the body, 
is called the Superior, or Descending Vena Cava, 
The other, which comes from the lower parts of the 
body, is called the Inferior^ ov Ascending Vena Cava, 

The veins which correspond with the branches of 
the Pulmonary Artery, and return to the heart the 
blood of the lungs, are four in number : two of them 
proceeding from each lung. They are called Pul- 
monary Veins. 

In many of the veins there are valves, which pre- 
vent the blood they contain from moving towards the 
surface and extremities of the body, but allow it to 
pass towards the heart without impediment. 

From the construction of the cavities of the heart, 
and the position of the valves which are in them ; as 
w^ell as the situation of the valves at the commence- 
ment of the g7'eat arteries, and the above mentioned 
valves of the veins, it is evident, that when the blood 
circulates, it must move from the heart, through the 
aorta and its branches, to the difiPerent parts of the 
body, and return from these parts through the vense 
cavse to the heart ; that, when deposited in the heart 
by the venae cavje, it must proceed through the pul- 
monary artery to the lungs, and return from the 
lungs through the pulmonary veins to the heart, in 
order to pass again from that organ into the aorta. 

It is also certain, that the blood is forced from the 
heart into the arteries, by the contraction of the mus- 
cular fibres of which the heart is composed ; and that 
the blood vessels likewise perform a part in the cir- 
culation, they propelling the blood which is thus 
thrown into them : but their action appears to depend 
upon causes of a complex nature. 



CHAPTER I. 

OF THE GENEHAL STRUCTURE AND ARRANGEMENT OF 
THE BLOOD VESSELS. 

SECTION I. 

Of the Ai'teries. 

The arteries are so much concerned in the im- 
portant function of the circulation of the blood, that 
every circumstance connected with them is very in- 
teresting. 

They are composed of coats or tunics, which are 
very elastic and strong, and which are also very 
thick. In consequence of the firmness of their coats, 
they continue open, after their contents are discharg= 
ed, like hai'd tubes. They submit to great dilata* 
tion, and elongation^ when fluids are forced into 
them, and return to their former dimensions when 
the distending cause is withdrawn. This elasticity 
is particularly subservient to the circulation of the 
blood. It admits the artery to distend readily, and 
receive the blood which is thrown into it by the con- 
traction of the heart. Ct also produces the contrac- 
tion of the artery ; which takes place as soon as the 
action of the heart ceases ; and this contraction of 
the artery necessarily forces the blood forward, as 
the valves at its orifice prevent it from returning to 
the heart. 

The motion of the artery, which is so easily per- 
ceived by the touch, and in many instances also by 
the eye, is completely explained by the discharge of 
blood into the artery from the heart, and by the 

Vol, II. 29 



226 Structwe of the Arteries, 

elasticity of the vessel, by which it re- acts upon the 
blood. In some cases it is not simply the diameter 
of the artery wliicij is enlarged, but a portion of the 
vessel is elongated ; and this elongation, by pro- 
ducing a curvature of it, renders its motion more 
visible. 

In the aorta, and probably in its large branches^ 
Elasticity seems to be the principal cause of the con- 
tinuance of the motion which is originally given to 
the blood by th& heart. But there are many circum- 
stances connected with the smaller vessels, which 
evince that they exert a power which is very differ- 
ent indeed from elasticity. Thus the application of 
local stimulants or rubefacients, and of heat, is fol- 
lowed by an increase of motion in the arteries of the 
parts to which they are applied. Neither of these 
causes could produce their effect by the influence of 
elasticity : but the effect of these and other similar 
causes is uniformly produced ; and a power of inde- 
pendent motion, or Irritability, is thus proved to 
exist in these vessels, and seems essentially neces- 
sary to the circulation of the blood. 

Tlie Structure of the Arteries 

Is, therefore, a subject of importance, and has re- 
ceived a considerable degree of attention from anato- 
mists. 

They are composed of a dense elastic substance, 
of a whitish colour. Their external surface is rough, 
and iutimately connected with the cellular membrane, 
which every where surrounds it in varying quanti- 
ties. Internally, they are lined with a thin mem- 
brane, which is very smooth and flexible, and is also 
very elastic. The substance which composes the 
artery, and is situated between the cellular invest- 
ment and the internal membrane, consists of fibres, 
which are nearly, though not completely, circular, 



Structure of the Arteries. 22/ 

but so arranged as to constitute a cylinder. These 
fibres may 'oe separated from each other so as to 
form laminae, which have been considered as differ- 
ent coats of the arteries ; but there is no arran2:e= 
ment of them which composes regular distinct strata. 
The coats of arteries may, therefore, be separated 
into a greater or smaller number of laminae, according 
to the thickness of these laminai. 

The fibres wliich compose these laminae appear to 
be united to each other in a way which readily al- 
lows of their separation, at the same time that they 
form a firm texture. Although arteries thus appear 
essentially diflerent from muscles in their hardness 
and their elasticity, as well as in their general tex- 
ture, they are considered, by a great majority of 
anatomists, as partaking more or less of a muscular 
structure. 

In the human subject their structure is very diifi- 
cult of demonstration, and great differences exist in 
the accounts wliich are given of it, even by anato- 
mists, who agree in the general sentiment that the 
arteries are muscular. 

Thus Haller believed that muscular fibres were 
most abundant in the large arteries, while J. Hunter 
thought the reverse. 

Hunter appears to have investigated this subject 
with great attention, and supposed the muscular 
substance, in the composition of arteries, to be inte- 
rior, and the elastic matter exterior ; that in large 
arteries this muscular substance is very small in 
fjuatitity, and gradually increases in proportion as 
the artery diminishes in size. He however observes, 
that lie never could discover the direction of the mus- 
cular fibres.'^ 

When the great talents of Mr. Hunter as an 

• Treatise on the Blood, &c. Vol. I. p. 113. Bradford's cditioli. 



228 Question respecting the muscularity of Arteries. 

anatomist, are considered, this circumstance cannot 
fail to excite a belief that the existence of these 
fibres is not certain : and if to this be added the fact, 
that even the red coloured substance of the arteries 
is elastic, and in that respect different from muscu- 
lar substance, the reasons for doubting must be in- 
creased. 

Bichat appears to have entertained very strong 
doubts on the subject ; but he stands almost alone ; 
for a large number both of the preceding and cotem- 
porary anatomists, seem to have adopted the senti- 
ment, that the arteries have a muscular structure. 

The student of anatomy can very easily examine 
this subject himself, by separating the coats of ar- 
teries into different laminae ; and by viewing the 
edges of the transverse and longitudinal sections of 
those vessels. While thus engaged with this ques- 
tion, he will read with great advantage Avhat has 
been written upon it by Mr. Hunter, in his Treatise 
on the Blood, &c. See chapter second, section 3. 
Bichat ought also to be read upon this subject, which 
he has discussed in his Anatomic Generate^— System 
Vasculaire a Sang Rouge, article Troisiemc, &c. and 
also in his Traite des Membranes, article Sixieme. 

The belief of the irritability of arteries does not, 
however, rest upon the appearance of their fibres. 

1. It is asserted by very respectable authors,* 
that they have been made to contract by the appli- 
cation of mechanical and of cliemical irritation, and 
also of the electric and galvanic power. 

2. A partial or local action of arteries is often 
produced by the local application of heat and rube- 
facients, as has been already observed. 



* See Soemmering on the structure of the Human Body. Vol. IV. 
German edition. Dr. Jones on the Process employed by nature for 
suppressing Hsemorrhage, Sec. 



Proofs of the IrritabiUty of the ArteHes, S29 

3. Arterial acdoa is often suspended in a particu- 
lar part by the application of cold. It has also been 
observed that the arteries have for a short time ceas- 
ed to pulsate in cases of extreme contusion and la- 
ceration of the limbs.* 

4. When arteries are divided transversely in living 
animals, they often contract so as to close completely 
the orifice made by the division. 

5. In a horse bled to death, it was ascertained by 
Mr. Hunter, that the transverse diameter of the arte- 
ries was diminished to a degree that could not be 
explained by their elasticity. He also found that, 
after death, the arteries, especially those of the 
smaller size, are generally in a state of contraction, 
which is greater than can be explained by their elas- 
ticity : for if they are distended mechanically, they 
do not contract again to their former size, but conti- 
nue of a larger diameter than they were before tha 
distention ; although their elasticity may act so as to 
restore a very considerable degree of the contraction 
observed at death. 

The contraction, which is thus done away by dis- 
tention, Mr. Hunter supposed to have been produced 
by muscular fibres : for, if it had been dependent on 
elasticity, it must have re-appeared when the dis- 
tending power was withdrawn. 

It therefore seems certain, that the arteries have a 
power of contraction different from that which de- 
pends upon elasticity; but whether this depends 
upon muscular fibres superadded to them, or upon 
an irritable quality in the ordinary elastic fibres of 
blood vessels, is a question which is not perhaps 
completely decided. 

♦ This local suspension of arterial motion by cold, 8:c., applied 
locally, is very difficult to explain ; as the action of the heart and the 
elasticity of the arteries appear sufficient to account for the pulsa- 
tion of the large arteries. 



230 General Observations on the AiHeries, 

The motion of the blood in the arteries appears to 
depend, 

1st, Upon the impulse given to it by the action of 
Die heart. 

2dly, Upon the elasticity of the arteries, in conse- 
quence of which they first give way to the blood 
impelled into tliem, and then re-act upon it; and 

Sdly, Upon the power of contraction in the arte- 
ries, or their irritability. 

In the larger arteries the blood seems to move as 
it would through an inanimate elastic tube, in conse- 
quence of the impulse given by the heart, and kept 
up by the arteries themselves. In the smaller ves- 
sels it seems probable that the motion of the blood 
depends in a considerable degree upon the contrac- 
tion vvliich arises from their irritability. 

Tlie obvious effect of tlie elasticity of the arteries 
is to resist distention and elongation, and to contract 
the artery to its natural state, when the distending 
or elongating cause ceases to act. Eut it must also 
resist the contraction induced by the muscular fibres, 
and restore the artery to its natural size when the 
muscular fibres cease to act after contracting it, as 
has been observed by Mr. Hunter. 

It seems probable that all the fibres of which the 
artery consists are nearly but not completely circu- 
lar ; for it is not certain that there are any longitudi- 
nal fibres in the stiucture of an artery. 

The internal coat of these vessels is very smootli, 
but extremely dense and firm ; and seems to be ren- 
dered moist and flexible by an exudation on its sur- 
face. It adheres very closely to the contiguous fibres 
of the coat exterior to it, but may be very readily 
peeled off from them. It is of a whitish colour, 
and, like the fibrous structure of the artery, is very 
elastic. Like th??t substance also it is easily torn or 
broken, and, when ligatures have been applied to 



General Observations on the Arteries: 231 

arteries, it has been often observed that the fibrous 
structure and the internal coat have been separated, 
while this external cellular coat has remained en- 
tire. 

The arteries are supplied with their proper blood 
vessels and lymphatics. It is to be observed, tbat 
the blood vessels are not derived from the artery 
on which they run, but from the contii:;uous vessels. 

These vessels iiave nerves also, which are rather 
small in size, when compared with those which go 
to other parts. 

Arteries appear to have a cylindrical form, for no 
diminution of diameter is observable in those portions 
of them which send off no ramifications. 

When an artery ramifies, the area of the differ- 
ent branches exceeds considerably that of the main 
trunk. Upon this principle the aorta and its branch- 
es have been compared to a cone, the basis of which 
is formed by the branches, and the apex of the 
trunk.* 

The transverse section of an artery is circular. 

There are no valves in the arteries, except those 
of the orifices of the aorta and the pulmonary artery, 
at the heart. The valves of the pulmonary artery 
have been described in the 51st page of this volume, 
and those of the aorta have an exact resemblance to 
them, but are rather larger. 

The co'irse of the arteries throughout the body is 
obviously calculated to prevent their exposure to 
pressure, or to great extension from the flexure of the 
articulations by which they pass. With this view 
they sometimes proceed in a winding direction ; and 
when they pass over parts which are subject to great 

* According toBrussiere the relation of the branches of the aorta 
to its trunk, is as 25 to 16 : Helvetius reckons the orifice of the aorta 
in comparison with its branches as 64 to 72- Lassus— Ed- 



232 General Observations on the Arteries, 

distention or enlargement, as the cheeks, they often 
meander ; and, therefore, their length may be in- 
creased by straightening, without stretching them. 

Their course apppears sometimes to have been 
calculated to lessen the force of the blood, as is the 
case with the Internal Carotid and the Vei'tebral ar- 
teries. 

In the trunk of the body the branches of arteries 
generally form obtuse angles with the trunks from 
which they proceed. In the limbs these angles are 
acute. 

The communication of arteries with each other is 
termed Anastomosis. In some instances, two branch- 
es which proceed in a course nearly similar, unite 
with an acute angle, and form one common trunk. 
Sometimes, a transverse branch runs from one to the 
other, so as to form a right angle with each. In 
other cases, the two anastaraosing branches form an 
arch, or portion of a circle, from which many 
branches go off. 

By successive ramifications, arteries gradually di- 
minish in size, until they are finally extremely small. 

The smallest arteries do not carry red blood, their 
diameters being smaller than those of the red parti- 
cles of that fluid, the serous or aqueous part of the 
blood can, therefore, only pass through them. 

Many of the arteries which carry red blood, and 
of the last mentioned serous arteries terminate in 
reins, which are in some respects, a continuation of 
i\\t tube reflected backwards.* 

f Malpighi and Leeuwenhoek declare, that by the aid of a mi- 
croscope, they have seen arteries terminating in the veins. Haller 
advances formally his own experience in support of his assertion. 
Other anatomists have seen, that in blowing into an artery, the air 
passed into the corresponding veins. Nevertheless Derverney and 
some others say, that a particular substance is interposed between, 
the extremities of these vessels. Ruysch in his Thesaurus Anato- 
micus VI. No. 73, says in repletione arteriarum, replentur estplu? 
rimum quosque vense, et vice versa, ita ut impossibile videatur prae- 
cise dicere quomodo res se habeat, Discours sur I'Anat.— Ed. 



General Observations on the Veins. 23S 

Tbey likewise terminate in exlialent vessels, which 
open upon the external surface, and upon the various 
internal surfaces of the body. The secretory vessels 
of glands are likewise the termination of many ar- 
teries. 



SECTION II. 

Of the Feins, 

These tubes, which return to the heart the blood 
carried from it by the arteries, are more numerous 
than the arteries, and often are larger in diameter. 

They generally accompany the arteries, and very 
often two veins are found with one artery. 

In addition to these last mentioned veins, which 
may be called deep-seated, there are many subcuta- 
neous veins which appear on almost every part of 
the surface of the body. 

The capacity of all the veins is therefore much 
greater than that of all the arteries. 

Those subcutaneous veins, which are of consi- 
derable size, communicate very freely with each 
other, and also with the deep-seated veins. 

Tlie trunks of the veins, in those places where no 
branches go off, are generally cylindrical. There 
are, however, some exceptions, in which these ves- 
sels are irregularly dilated, as sometimes happens 
in the case of the internal jugular vein. It is, how- 
ever, not easy to determine from the appearance of 
veins injected after death, respecting their situation 
during life, as their coats are very yielding ; and it 
is very probable that they are, therefore, preterna- 
turally dilated by the injection. 

Veins, directly or indirectly, originate from the 
termination of arteries : but they do not pulsate as 
the arteries do, because the impulse given to the 

Vol. 11. 30 



334 Coats of Veins, 

blood by the heart is very much diminished in con- 
sequence of the great dimirmtion of the size of the 
vessels through which the blood has passed. 

In some cases, however, when blood flows from 
an opened vein; the extent of its projection is alter- 
jiately increased and diminished, in quick succes- 
sion, as if it were influenced by the pulsation of the 
heart. 

The Coats of Veins differ considerably from those 
of Arteries^ — for they are thinner, and so much less 
firm, that veins, unlike arteries, collapse when they 
are empty. 

They consist of a dense elastic substance, the 
fibres of which are much less distinct than those of 
arteries, but some of them are to be seen in a longi- 
tudinal direction. These fibres can be made to con- 
tract by local irritation ; for if a vein be laid bare in 
a living animal, and then punctured, it will often 
contract so as to diminish its diameter very consi- 
derably, although no blood shall have escaped from 
the punctures. 

Next to the elastic substance is the internal coat, 
which is smooth and polished. It is separated from 
the substance exterior to it with difficulty, although 
it may be taken from it very easily in the vena cava. 
f^ This internal coat is more ostensible than the in- 
ternal coat of arteries, and is not, like the latter, dis- 
posed to ossification. It is frequently so arranged 
as to form valves, which are plaits or folds, of a 
semilunar form, that project from the surfaces into 
the cavities of these vessels.* 

Two of these valves are generally placed opposite 

* The valves of the veins were first described by Charles Etieme 
©f Paris in 1546. In 1547, Amatus, a Portuguese, saw at Ferrary 
those at the mouth of the vena azygos. Sylvius of Paris announced 
them about the same time in the jugular, brachial and crural veins. 
Fabricius Aquapendente claims the discovery for himself in 157'4 
Lassus. — Ed. 



Colour of the Blood in the Veins » 235 

to each other; and, when raised up, they form a 
septum in the cylindrical cavity of the vessel. The 
septuui, thus composed, is concave towards the heart. 

The valves have a great effect in preventing the 
contents of the veins from moving in a retrograde 
course : they, therefore, necessarily modify the ef- 
fects of lateral pressure, in such a manner, that it 
propels the blood forward, or to the heart. 

These valves are generally found in the veins of 
the muscular parts of the body, especially in those 
of the extremities. They are not found in those 
veins which are in the cavities of the body, nor ia 
the internal jugulars. — They are placed at unequal 
distances from each other. 

The coats of the veins are somewhat transparent; 
and, therefore, those veins which are subcutaneous 
have a bluish aspect, which is derived from the co* 
lour of the blood they contain. 

The colour of the blood in the veins is difPerent 
from that in the arteries, being of a darker red. 

The situation and arrangement of the large trunks 
of veins is much alike in different subjects ; but the 
branches, especially those which are subcutaneous, 
are very variable in their situations. 



CHAPTER II. 

A PARTICULAR ACCOUNT OF THE DISTRIBUTION OP THF, 
ARTERIES. 

SECTION I. 

Of the AORTA,* 

Or the Great Trunk of the Arterial System. 

When the heart is in its natural position, the 
right ventricle is nearly anterior to the left, and, 
therefore, the aorta, where it originates from the 
left ventricle, is behind the pulmonary artery, and 
covered by it^ Its first direction is so oblique 
towards the right side of the body, that it crosses the 
pulmonary artery behind, and appears on the right 
side of it. It has scarcely assumed this position 
before its course alters, for it then proceeds obliquely 
backwards, and to the left; so as to form a large 
curve or arch, which extends to the left of the spine. 

The position of this curve or arch is so oblique, 
with respect to the body, that the cord or diameter 
of it, if it were extended anteriorly and posteriorly, 
would strike the cartilage of the second or third right 
rib about the middle of its length, and the left rib 
near the head. In consequence of this position of 
the curve, the aorta crosses over the right branch 
of tiie pulmonary artery, and the left branch of the 
windpipe : and assumes a situation, in front, and to 
the left of the third dorsal vertebra : from this situa- 
tion it proceeds downwards ; in front, but rather on 

* This name was given by Aristotle.— Eo, 



A TABLE 



EXHIBITING THE DISTRIBUTION OF THE BRANCHES OF THE AORTA 



e spent Upon the siibsUnce of the Heart. 



ilidsarc appropriated i 



the thyroid cartjbge, i 



/ The superior Thy- .„ 5 ''"h^ Thyroid Gknd. The Larynx. 

roid Arkry I The parts contiguous to the Os Hyoidoa. 

The Sublingual S '^'"^ Tongue. Sublingual Gland. The Pl.«. 

The Facial < The side of the Face, Chin. Lips. Parta under 

contiguous parts. 



_.__ .rri 

head, anJ the ii[i])cftpai 



The INTERNAL CJlROTW, 
which is iipiiropriuted to the 



Inferior Pharyngeal J^J^ ra'vh^"of the ( 



le Internal Maxillary J p 
:e Temporal \ 



lalJy 



.The Ophthalmic Artery, to the Eye s 
The Anterior Artery ofSxhoanter 

the Brain 2 

The Middle Artery of C The middl 

th^Dram X of the C 



1 its appendages. 
■ portion of tlie Cerebrum, 
and part of the posterior portiu 



33 o- 

o - 

< I 



The LEFT SUBCl^riAN. 



The 



r Anterior portion ofth 

t rax. TheMammT 
rCereb," " 

,ej ten. 
t Cer 



The Vcrtebml to the 

The Infe 

The Superior Inter-J Someofthelnterc'ostal 
costal, to ( 

The Cervical, 



■rebnim- 
Gla 
(Esophagus. ^ 



C Neck. 



rMusclesoftheNcck. 
Thelcapularyitothe-sDo. on the dorsum o 
L C *'>e Scapula. . 



r The BnoNCHiii. arteries ...... To the Trachea and substaoce of the Lungs. 

, The (EnQphageal ■ . . - ' - - ■ To the (Esophagus, 

The Phrenic Aruriei To the diaphragm. 

C(ELIAC ARTERY Tothestomach,liver, andspleen. 

SUPERIOR MESENTERIC . - - . Almost all the small intestines, and part of the great. 

Capsular Artenet ...-..- Glandulie Renalea. 

EMULGENTS The Kidneys. 

Sptrwalies The Testicles. The Ovaries. 

l^FERion MtsEKTiRics ...... The left portion of the Coloi), and the Rectum. 

Lumbar Artmes ....... Muscles on tlie loins and the abdomen. The spine and the spinal C 

^, The aiDDLE iachal .-..--. Which is spent upon the Sacrum, Coccyx, ana Rectum, 



The INTERNAL ILIAC, 

Which tend* off 



T/u Rio Lumbar artery 



The Sacrum, internally and i 

Equini. 
The Bb( 



,^SThe 

TThc Sac 

to^ ternall; 

CThe Caui 

CThe Bbdder. 
to-^ The Uterus. 

f The Muscles on tlie uppe 
to< interior part of the thigh, 
^Thc Hip joint. &c. 

TT 



by tho Ischiatic ) i 



L" Organs of Generation 



The EXTERNAL ILIAC. 

fbe fir« portion of the gres 
artery of the lower extremity, 
which passes under Pouparl's ' 
ligament to the Uiigh, but 



TAe CiTCvmJltza 
\ small artery, wh 

tiguous portions u 



intcic and the External 
'cctoral and other 

The Scapulary Artery, 



t of the 



of the Ob Humeri. 



e Profunda Humeri 



e Elbow It gi' 



Branc 


est 


the muscles in 


To the 


7hlo 


branch, 
the thumb. 
Isitle ofthcinde 
IS profundus. 


To the 


wr'is' 


and the hand. 


Arecu 


rren 


branch. 



nity begins at Pou- 
lart'shgainenl. It 
lends off 



The Estem:dPui 
the Organs ot^G 

The Profunda, 



3;;^r^ 



terior part of the leg to i 
top of Ihi.- foot, from wh 
It descends to the sole. 




rhe arcus sublimis in the palm of 
the hand, which sends olT the 
digital arteries to the sides of 



M 



Situation of the Aorta in the Thorax and Abdotnen. 237 

the left side of the spine;, and in contact with that 
column. 

The AORTA, as well as the Pulmonary Artery, 
for a small distance from the heart, is invested hy 
the pericardium ; and, Avhen that sac is opened, ap- 
pears to be contained in it. 

After crossing the right branch of the Pulmonary 
Artery , a ligament is inserted into it, which proceeds 
from the main trunk of the pulmonary artery at its 
division : this ligament was the Canalis Arteriosus 
in the foetus. 

As the AORTA proceeds down the spine, it is 
situated between the two laminae of the mediastinum, 
and in contact with the left lamina, through which it 
may be seen. It descends between the crura of tha 
diaphragm, in a vacuity which is sufficiently large 
to admit of its passage without pressure from the 
surrounding parts, and is still in contact with the 
anterior surface of the spine, but rather to the left of 
the middle of it. It continues this course along the 
spine until it arrives at the cartilaginous substance 
between the fourth and fifth lumbar vertebrae, when 
it divides into two great branches of equal size, 
which form an acute angle with each other. These 
are denominated the common, or primitive iliac 
Arteries. 

From the aorta in this course are sent off the 
arteries which are distributed to all the parts of the 
body for their nourishment and animation. 

From the curve proceed the great branches which 
supply the heart, the liead, the upper extremities, 
and part of the thorax. Between the curve and the 
great primitive iliac arteries, the aorta sends off 
those branches which supply the viscera contained 
in the cavities of the thorax and abdomen,* and part 

• It ought to be observed lietc, that the viscera in the lower part 
of the pelvis receive some branches from the internal iliac arteries. 



t 



S38 Origin of the Subclavian and Carotid Arteries, 

of the trunk of the body. The great ILIAC 
branches of the AORTA are cUvided into smaller 
arteries, which supply the whole of the lower ex- 
tremities and some of the viscera of the pelvis. 

SECTION II. 

Of the Branches which go off from the arch of the 
I AORTA. 

The proper arteries of the heart, denominated co- 
ronary ARTERIES, proceed from the aorta so 
near to the heart that their orifices are covered by 
the semilunar valves, when those valves are pressed 
against the sides of the artery. These arteries have 
been described in the account of the heart. — See 
p. 50. 

The arteries of the head and of the upper extre- 
mities proceed from the upper part of the curve in 
the following manner. 

A large trunk, called arteria innominata, goes 
off first. This is more than sixteen lines in length, 
when it divides into two branches : one of which 
supplies the right side of the head, and is denomi- 
nated the right carotid : the other proceeds to the 
right arm, and from its course under the clavicle, is 
called, at first, the right subclavian. Almost in 
contact with the first trunk, another artery goes off, 
which proceeds to the left side of the head, and is call- 
ed the LEFT CAROTID. Vtry near to this, arises the 
third artery, which proceeds to the left arm, and is 
denominated the left subclavian. From these great 
branches originate the blood vessels, which are spent 
upon the head and neck and the upper extremities. 

As these arteries arise from the curve of the 
aorta, they are situated obliquely with respect to 
each other. The artebia innominata is not only 



% 



Situatio7i of the Common Carotid Arteries. 239 

to the right, but it is also anterior to the two others : 
and the left subclavian is posterior, as well as to 
the left of the left carotid and the arteria inno- 

MINATA. 

THE CAROTID ARTERIES. 

The two carotid arteries above mentioned have 
been denominated common carotids, to distinguish 
them from their first ramifications, which are called 
internal and external carotids. 

THE COMMON CAROTIDS 

Proceed towards the head on each side of the tra- 
chea : at first they diverge, but they soon become 
nearly parallel to each other, and continue so until 
they have asceuded as iiigh as the upper edge of the 
thyroid cartilage, when they divide into the inter- 
nal and external carotids. 

These arteries are at first very near each other, 
and rather in front of the trachea ; they gradually 
diverge and pass backwards and outwards on the 
sides of it, and of the oesophagus, until they have ar- 
rived at the larynx. In the lower part of the neck 
they are covered by the sterno mastoidei, the sterno 
hyoidei, and thyroidei, as well as by the platysma 
rayoidei muscles. Above, their situation is more su- 
perficial ; and they are immediately under the pla- 
tysma myoides. 

On the inside, they are very near the trachea and 
larynx, and the oesophagus ; on the outside, and ra- 
ther anterior to them, are the internal jugular veins ; 
and behind, on each side, are two important nerves 
called the intercostal and the par vagum. These 
blood vessels and nerves are surrounded by absorb- 
ent vessels. 



240 External Carotid Artery. 

The COMMON CAROTID ARTERIES Send off HO 
branches from their origin to their bifurcation ; and 
they appear to preserve the same diameter through- 
out their whole extent. In some few instances the 
right carotid has been found larger than the left. 
The external and internal branches into w^hich they 
divide, are nearly equal in the adult ; but it is sup- 
posed that the internal is the largest during infancy. 
The relative position of these branches is also dif- 
ferent at the commencement from what it is after- 
wards. The INTERNAL CAROTID forms a curve which 
projects outwardly, so as to be exterior to the ex- 
ternal CAROTID, while this last proceeds upwards, 
and rather backwards. 

THE EXTERJVAL CAROTID ARTERY 

May be considered as extending from its commence- 
ment, which is on a line with the superior margin of 
the thyroid cartilage, to the neck of the condyle of 
the lower jaw, or near it. 

At first it is superficial ; but as it proceeds up- 
wards it becomes deep-seated : and passing under 
the digastric and stylo-hyoidei muscles, and the 
ninth pair of nerves, is covered by the Parotid 
Gland. After this, it again becomes superficial; for 
the temporal artery, which may be regarded as the 
continuation of the external carotid, passes over the 
zygomatic process of the temporal bone. 

As the external carotid supplies with blood the 
upper part of the neck and throat, the exterior of the 
head and face, and the inside of the mouth and nose ; 
its branches must necessarily be numerous, and must 
pass in very various directions. 

Thus, soon after its commencement, it sends off, 
in an anterior direction, three large branches ; viz. to 
the upper part of the neck, to the parts within the lower 
jaw, and to the cheeks and lips. These are deno- 



External Carotid and its Branches. S-ll 

ininated, the superior thyroid, the sublingual^ 
and the facial. It then sends off to the back of 
the head one which is called the occipital ; and, 
as it proceeds upwards near the condyle of the lower 
jaw, another which passes interitally, behind the 
jaw, to the deep seated parts in that direction. Af- 
ter this, it forms the temporal artery, which supplies 
the forehead and central parts of the cranium. Be- 
sides these larger branches, the external carotid 
sends off two which are smaller; one from near the 
origin of the sublingual artery, which is spent prin- 
cipally upon the pharynx and fauces, and is called 
the iNff:RioR PHARYNGEAL : and another, while it is 
involved with the parotid gland, which goes to the 
ear ; and is therefore called posterior auris. 

These arteries are distributed in the following 
manner : 

1. The superior thyroid branch 

Comes off very near the root of the external carotid, 
and sometimes from the common trunk ; it runs ob- 
liquely downwards and forwards, in a meandering 
course, to tiie thyroid gland, where it is spent. 
During this course it sends off one branch to the 
parts contiguous to the os hyoides ; another to the 
neighbourhood of the larynx : and a third branch, 
which may be termesd laryngeal, that passes with a 
small nerve derived from the laryngeal branch of the 
par vagura, either between the os hyoides and thy- 
roid cartilage, or the thyroid and cricoid cartilages, 
to the interior muscles of the larynx; and finally 
returns again to terminate externally. 

While in the thyroid gland this artery anasto- 
moses with the inferior thyroid, and also with its 
fellow on the opposite side. 

Vol. it. 31 



S42 Branches of the External Carotid, 
2. The LINGUAL, or sublingual branch, 

Goes off above the last mentioned artery, and very 
near it ; but in a very different direction, for it runs 
upwards and forwards, to the tongue. In tliis course 
it crosses obliquely the os hyoides, and is commonly 
■within the hyoglossus muscle. It gives off branches 
to the middle constrictors of the pharynx, and to the 
muscles contiguous to the tongue. It also sends off 
a branch which penetrates to the back of the tongue, 
which is called, from its situation, Dorsalis Linguae. 
At the anterior margin of the hyoglossus muscle it 
divides into two branches, one of which passes to 
the sublingual gland and the adjacent parts, aud is 
thence c'dWed Sublingual ; while the other branch, 
the Banina, passes by the side of the genio glossus 
muscle to the apex of the tongue, 

8. The facial or external maxillary, 

Huns obliquely upwards and forwards under the 
ninth pair of nerves, the stylo hyoideus muscle and 
the tendon of the digastric, across the lower jaw and 
cheek, towards the inner orner of the eye, in a ser- 
pentine course. Before it crosses the jaw it sends off 
several branches, viz. to the pharynx, the tonsils, the 
inferior maxillar> gland and the parts contiguous to 
it. It also sends a branch towards the chin, which 
passes between the mylo hyoideus, the anterior belly 
of the digastric, and the margin of the lower jaw. 
and «!ome of its branches continue to the muscles of 
the under lip. This branch is called the SubmenfaL 
This artery then passes round the basis or inferior 
edge of the lower jaw, very near the anterior margin 
of the masseter muscle, and is so superficial that its 
pulsations can be readily perceived After this turn, 
its course is obliquely upwards and ftn-wards. Near 
the basis of the jaw it sends off a branch to the mas-; 



Branches of the External Carotid. 243 

seter, whicli anastomoses with small branches from 
the temporal ; and another which passes superficially 
to the under lip and contis^uous parts of the cheeks. 
This last is called the Inferior Labial. 

After the artery has passed as high as the teeth in 
the lower jaw, it divides into two branches ; which 
go, one to the under, and the other to the upper lip : 
that to the upper lip is largest. These branches are 
called Coronary. 

■ The Coronary Artery of the lower lip passes under 
the muscles called Depressor Anguli 0?^is, and Or- 
bicularis Oris, into the substance of the lip. and 
anastomoses with its fellow of the opposite side. 

The Coronary Artery of the upper lip passes un- 
der the zygomaticus major and the orbicularis, and 
very near the margin of the uj)per lip internally. It 
also anastomoses freely with its fellow on the oppo- 
site side. These anastomoses are frequently so con- 
sideral)le that the arteries on one side can be well 
filled by injecting those of the other. The coronary 
branches, as well as the main trunk of the facial ar- 
tery, observe a serpentine or tortuous course; in con- 
sequence of which they admit of the motions of the 
checks and lips, which they would greatly impede if 
they were straight. 

From the upper coronary artery a branch con- 
tinues in the direction of the main trunk of the fa- 
cial artery, by the side of the nose, which extends up- 
wards, sendng off small branches in its course, and 
finally terminates about the internal angle of the eye 
and the forehead. 

4. The INFERIOR PHARYNGEAL 

Is a very small artery ; it arises posteriorly from the 
external carotid, opposite to the origin of the sublin- 
gual, and passes upwards to the basis of the era- 



24j4 Branches of the External Carotid, 

nium. la this coarse it sends several branches to the 
pharynx, and to the deep seated parts immediately 
contiguous. 

It also sends branches to the first ganglion of the 
intercostal nerve, to the par vagum, and to the lym- 
phatic glands of the neck ; and finally it enters the 
cavity of the cranium by the posterior foramen la- 
cerum. 

In some cases it also sends a small branch through 
the anterior foramen lacerura. 

5. The OCCIPITAL artery 

Arises from the posterior side of the external caro- 
tid, nearly opposite to the facial, but sometimes 
higher up ; it ascends obliquely, and passes to the 
back part of the cranium, between the transverse 
process of the atlas and the mastoid process of the 
temporal bone. 

In this course it passes over the internal jugular 
vein and the eightli pair of nerves, and under the 
posterior part of the digastric muscle ; it lies very 
near to the base of the mastoid process, and under 
the muscles which are inserted into it. After emerg- 
ing from these muscles, it runs superficially upon 
the occiput, dividing into branches which extend to 
those of the temporal artery. 

The OCCIPITAL ARTERY seuds off branches to the 
muscles which are contiguons to it, and to the glands 
of the neck. 

It also gives off the following branches : One 
called the Meningeal, which passes through the 
posterior foramen lacerum to the under and back 
part of the dura mater : one to the exterior parts of 
the ear : another which passes downwards, and is 
spent upon the complexus, trachelo mastoideus, and 
other muscles of the neck : and several smaller ar= 
terieso 



BfcMches of the External Carotid. '245 

The artery next to be described, is sometimes sent 
off by the occipital artery. 

6. The POSTERIOR auricular, or stylo mastoid 

ARTERY, 

When it arises from the external carotid, comes off 
posteriorly from the artery, where it is involved with 
the parotid gland, and passes backwards between 
the meatus auditorius externiis and the mastoid pro- 
cess. It then ascends, in a curved direction, and 
terminates behind the ear. 

In this course it sends off small branches to the 
parotid gland, and to t!ie digastric and steruo mas- 
toid muscles. Sometimes a distinct branch, which 
is particularly visible in children, passes through an 
aperture in the meatus auditorius externus, and is 
spent on its internal surface. 

It also sends off a branch which enters into the 
Stylo Mastoid Foramen^ and supplies small vessels 
to the membrana tympani and the lining membrane 
of the cavity of the tympanum ; to the mastoid cells ; 
to the muscle of the stapes, and to the external semi- 
circular canal. One of these vessels anastomoses, in 
the upper and posterior part of the cavity of the tyra» 
panum, with a small twig derived from the artery of 
the dura mater. When it has arrived behind the 
ear, the Posterior Auricular Artery terminates upon 
the external ear and the parts contiguous to it. 

7. The INTERNAL MAXILLARY ARTERY* 

Arises from the external carotid under the parotid 
gland, at a little distance below the neck of the con- 



* The general situation of this artery, and the distribution of se- 
veral of its most important branches, cannot be understood without 
a knowledge of the bones through which they pass. The student of 
surgery will therefore derive benefit from a re-examination of these 
bones, and of the zygomatic fossa, &c. when he studies this artery. 



246" The Interna! Maxillary Artery. 

dyloitl process of the lower jaw, and extends to the 
bottom of the zygomatic fossa ; varying its dir action 
in its course. It is rather larger than the temporal. 

A. It first sends off one or two small branches 
to the ear, and a twig which penetrates into the ca- 
vity of the tympanum by the glenoid fissure. 

B. It also sends off a small artery called the Less- 
er Meningeal, which passes upwards, and after 
giving branches to the external pterygoid anil the 
muscles of the palate, passes through the foramen 
ovale, and is spent upon the 'dura mater about the 
sella turcica. 

c. It then sends off one of its largest branches, the 
Great or Middle Artery of the Dura Mater, which 
passes in a straight direction to the foramen spinale, 
by which it enters into the cavity of the cranium. 

This artery ramifies largely on the dura mater, 
and makes those aborescent impressions which are 
so visible in the parietal bone. It generally divides 
into two great branches : the anterior, which is the 
largest, passes over the anterior and inferior angle of 
the parietal bone : the posterior branch soon divides 
into many ramifications, which are extended lateral- 
ly and posteriorly. 

It furnishes the twig which passes to the ear by 
the hiatus of Fallopius, and anastomoses with the 
small branches of the stylo mastoid artery. 

It also supplies some other small vessels which 
pass to the cavity of the tympanum by small forami- 
na near the junction of the squamous and petrous 
portions of the temporal bone. 

I). The next branch sent off by the internal max- 
illary leaves it about an inch from its origin, and is 

(See Vol. I. page 73.) — He ought to be well acquainted with this 
subjects if he should undertake the management of ntcvosis ot the 
jaw bones ; or- of those fungous tumours, which sometimes originate 
in the antrum maxiilare ; as well as of several other complaints 



Tlie Internal Maxillary Artery. -247 

called the Inferior Maxillary. It passes between 
the internal pterygoid muscle and the bone, and af- 
ter giving small branches to the contiguous muscles, 
enters the canal in the lower jaw, in company with 
the nerve. This canal has a very free communica- 
tion with the cellular structure of the jaw, and the 
artery in its progress along it sends branches to th,e 
respective teeth and tlie bone. At the anterior maxil- 
lary foramen, this artery sends otF a considerable 
branch, which passes out and anastomoses with the 
vessels on the chin, while another branch passes for- 
ward and supplies the canine and incisor teeth and 
the bone contiguous to them. 

Sometimes the inferior maxillary artery divides 
into two branches before it- has arrived at this fora- 
men. In this case, one of the arteries passes out of 
the foramen, while the other continues to the sym- 
phisis. 

E. Two branches pass off to the temporal muscle, 
which originate at a small distance from each other : 
one of them passes upwards on the tendon of the 
temporal muscle ; the other arises near the tuberosi- 
ty of the upper maxillary bone : they are called the 
exterior deep, and the interior deep temporal artery. 
They are both spent upon the temporal muscle; but 
tlie interior branch sends a small twig into the orbit 
of the eye. 

F. There are some small branches which pass to 
the Pterygoid Muscles and to the Masseter, which 
arise either from the internal maxillary artery, or 
from the anterior deep temporal. They are general- 
ly small, and often irregular. 

G. An artery, particularly appropriated to the 
cheek, perforates the buccinator muscle from within 
outwards, and generally terminates on the buccina- 
tor, the zygomaticus major and the muscles of the 
Jips, This Artery of the Cheek is very irregular in 



248 The Internal Maxillary Artery. 

its origin, sometimes arising from the internal maxil- 
lary, sometimes from the deep temporal, and some- 
times from the suborbitary, or from the alveolar 
artery, to be immediately described. 

H. The Alveolar Artery, or the Artery of the 
Upper Jaw, arises generally from the internal max- 
illary, but spmetimes from one of its branches. It 
winds round the tuberosity of the upper jaw, and 
sends branches to the buccinator muscle, to the bone 
and the gums, to the antrum highmorianum, and 
some of the molar teeth : and also to the teeth gene- 
rally, by means of a canal which is analogous to 
that of the lo^yer jaw. 

I. The Infta\orhitar Artery arises from the inter- 
nal maxillary in the zygomatic fossa, and soon enters 
the infra orbitary canal, through which it passes to 
the face, and emerges below the orbit of the eye, 
supplying the muscles in the vicinity, and anasto- 
mosing with tl)0 small ramifications of the two last 
described arteries, and also of the facial artery and 
the opthalraic. j 

This artery i(i its course sends off small twigs to 
the periosteum. |;he adipose membrane, and the mus- 
cles in the inferjor part of the orbit, and also to the 
great maxillary sinus or antrum highmorianum, and 
to the canine anji incisor teeth. 

J. The Palato Maxillary^ or Superior Palatine 
Artery^ arises also in the zygomatic fossa, and, de- 
scending behind the upper maxillary bone, enters 
the posterior palatine canal. It generally forms two 
branches, the largest of which advances forward, 
supplying the palate and gums, and finally sends a 
twig through the foramen incisivum to the nose, 
while the posterior branch, which is much smaller, 
supplies the velum pendulum palati. 

K. The Pterygo Palatine, or Superior Pharyngeal, 
is a small vessel ; which sometimes arises from the 



Temporal Artery. S49 

artery next to be raentioned. It is spent upon the 
upper part of the pharynx, and a branch passes 
through the pterygo palatine foramen, which is spent 
upon the arch of the palate and the contiguous parts. 
L. The INTERNAL MAXILLARY at length termi- 
nates in the Spheno- Palatine, or Large JVasal Arte- 
ry, which passes through the spheno-palatine fora- 
men to the back part of the nose. This artery 
sometimes separates into two branches before it en- 
ters the foramen ; sometimes it enters singly, and 
divides into two branches soon after; one of them is 
spread upon the septum, and the other upon the 
external side of the nose ; each of these branches 
ramifies very minutely upon the Schneiderian mem- 
brane and its process in the different sinuses, and 
also in the ethmoidal cells. 

8. The TEMPORAL ARTERY 

Is considered as the continuation of the external 
carotid, because it preserves the direction of the 
main trunk, although the internal maxillary is larger. 

After parting with the internal maxillary it pro- 
jects outwards ; and passing between the Meatus 
Auditorius Externus and the condyle of the lower 
jaw, continues upwards, behind the root of the zygo- 
matic process of the temporal bone, to the aponeuro- 
sis of the temporal muscle: on the outside of which, 
immediately under. the integuments, it divides into 
two large branches denominated anterior und poste- 
rior. 

Before this division the temporal artery sends off 
several branches of very different sizes. 

One, which is considerable in size, and called the 
Transverse Facial Branch, advances forwards across 
the neck of the condyle of the lower jaw, and giving 
small branches to the masseter, runs parallel to the 
parotid duct, and below it. This branch is spent 

Vol, II. 32 



250 Temfoi^al Jlrtery. — Internal Carotid. 

upon the musdes of the face, and anastomoses with 
the other vessels of that part. 

The temporal gives oiT small branches to the pa- 
rotid gland and to the articulation of the jaw. From 
the last mentioned branch small twigs pass to the 
ear, one of which enters the cavity of the typanum 
by the glenoid fissure. 

While tliis artery is on a line with the zygomia, it 
sends off a branch called \\\^ middle temporal artery, 
which penetrates the aponeurosis of the temporal 
muscle, and ramifies under it upon the muscle in an 
anterior direction. 

The two great branches of the temporal artery are 
distributed in the following manner. The Anterior 
passes up in a serpentine direction on the anterior 
part of the temple, and supplies the front side of the 
head, and the upper j)art of the forehead. 

The Posterior extends upwards and backwards, 
and supplies the scalp on the lateral and middle part 
of the cranium, and also the bone. 

Ramifications from each of these branches anasto- 
mose on the upper part of the cranium with those of 
its fellow of the opposite side. The anterior branch 
also anastomoses on the forehead with the facial and 
ophthalmic artery ; and the posterior branch with 
the occipital artery on the back part of the head. 

THE INTERNAL CAROTID ARTERY 

Is sometimes called the Artery of the Brain, as it is 
almost entirely appropriated to that viscus. 

From its origin to the commencement of its ramifi- 
cations the course of this blood vessel is peculiarly 
tortuous. In consequence of which the force of the 
blood in it is greatly diminished before it arrives at 
the brain. 

An instance of this curvature occurs immediately 



Curvatures of the Internal Carotid. S51 

after its separation from the external carotid, when 
it protrudes outwards so much as to be exterior to 
that vessel ; after this it ascends to the carotid canal, 
and in its course is in contact^, or very near the par 
vagum and intercostal nerves. 

The carotid canal in the os petrosuin is by no 
means straight ; it forms a semicircular curve, for- 
wards and inwards ; and its upper portion, which is 
nearly horizontal, opens obliquely against the body 
of the sphenoidal bone, at a small distance from it. 
Therefore, after the artery has passed through the 
canal, it must turn upwards to get fairly into the ca- 
vity of the cranium ; and of course, its direction 
while in the canal, forms almost a right angle with 
its direction before it enters, and after it emerges 
from it. 

In consequence of this curvature, much of the mo- 
mentum of the blood must be impressed upon the 
cranium. 

After the artery has arrived at the end of the ca- 
rotid canal, and has turned upwards to get within 
the cavity of the cranium, it bends forwards, and 
passes nearly in a horizontal direction, through the 
cavernous sinus on the side of the sella turcica, to 
the anterior clinoid process ; here it again forms a 
considerable curvcj which is directly upwards, and 
then it perforates the dura mater. 

These curvatures must also deprive the blood of 
the carotid of a portion of the momentum which it 
has retained after leaving the bone. 

The object of these various flexures of the internal 
carotid appears to be analogous to that of tlie Refe 
Mirab'de in certain quadrupeds, wliich is formed by 
tlie division of this artery into many small branches, 
that reunite again, without producing any other ef- 
fect tlian the diminution of the momentum of the 
blood. 



25S Ophthalmic Artery. 

During its course from the place of bifurcation to 
its entrance into the carotid canal, the internal caro- 
tid artery very rarely sends off any branches. In the 
canal it gives off a small twig which enters the ca- 
vity of the tympayium; and sometimes a second 
which unites with the Ptei'ygoid branch of the inter- 
nal maxillary. 

As it goes by the sella turcica, it passes through 
the cavernous sinuses, and gives off two branches 
which are called the Posterior and Jinterior Arte- 
ries of the Cavernous Sinus or Receptacle. 

The posterior branch goes to that part of the dura 
mater which is connected with the posterior clinoid 
process, and the cuneiform process of the occipital 
bone. It likewise gives branches to several of the 
nerves which are contiguous, and to the pituitary 
gland. 

The anterior artery also gives branches to the 
contiguous nerves, to the dura mater, and the pitui- 
tary gland. 

When the internal carotid turns upwards at the 
anterior clinoid process, it sends off the 

OPHTHALMIC ARTERY 

Which passes under the optic nerve through the 
foramen opticura into the orbit of the eye, and is 
about a line and a half in diameter. 

Although this artery enters the orbit under the 
optic nerve, it soon takes a position on the outside 
of it; but afterwards gradually proceeds to the inner 
side of the orbit, crossing over this nerve in an ob- 
lique direction, and finally passes out of the orbit 
near the internal angle. In tliis spiral course it 
sends off numerous branches, viz. 

A. To timse parts which are auxiliary to the eye. 

B. To the ball of tJie eye. 



Branches of the Ophthalmic Artery. 253 

c. To the cavity of the nose, through small fora- 
mina in the ethmoid bone, and 

D. To the forehead and external side of the nose. 

These branches generally go off in the following 
order. 

1. The Lachrymal artery arises soon after the 
ophthalmic arrives within the orbit, and passes 
above the abductor muscle to the lachrymal gland, 
where it terminates, sending off many small branches 
in its course. 

2. The Central artery of the retina also leaves 
the ophthalmic soon after its arrival in the orbit : it 
is a small vessel which penetrates into the centre of 
the optic nerve, and passing with it into the eye is 
spread upon the internal surface of the retina. Here 
it appears to terminate in the adult ; but in the foetus 
it is continued through the vitreous humour to the 
capsule of the crystalline lens. 

3. While the ophthalmic is passing over the optic 
nerve the brunches which enter the ball of the eye 
leave it. Their number varies, but they form three 
classes, viz. The Long Ciliary, the Short Ciliary^ 
and the Anterior Ciliary arteries, (See description 
of the eye, vol. i. p. 352) the supra orbitary and 
muscular branches leave it also near the same places. 

4. The Supra Orbitary Branch often gives off 
several muscular twigs : but it passes out of the orbit 
through the supra orbitar foramen, and generally 
divides into two branches, one of which is spent 
upon the periosteum, and the other upon the skin 
and muscles of the forehead. 

5. There are sometimes two ?nuscular b?'anches, a 
Superior and an Inferior. The superior branch is 
often deficient : when it exists it supplies the levator 
palpebral, the levator oculi, obliquus superior, &c. ; 
but these parts are often supplied by the branches 
above mentioned. The supra orbitar so frequently 



S54 Branches of the Ophthalmic Artery. 

gives off branches to the muscles that it has been 
called the Superior Muscular Branch. The inferior 
muscular branch is more constant. It commonly 
supplies the rectus inferior, the adductor, and the 
inferior oblique muscles, and also the lachrymal 
sac, and the lower eyelid, &c. 

When the artery is ou the inside of the nerve it 
sends off the two branches to the cavity of the nose, 
viz. The Ethmoidal Arteries ; and also, branches to 
the eyelids. 

6. The Posterior Ethmoidal branch is first. It 
passes between the levator and adductor muscles, 
and above the obliquus superior; and penetrates the 
cavity of the cranium by the posterior orbitary fora- 
men : after giving some twigs to the dura mater, it 
passes to the posterior cells of the ethmoid by the 
foramina of the cribriform plate of that bone, and 
sends a small branch to the Schneiderian membrane 
on the back part of the septum of the nose. 

7. The Anterior Ethmoidal artery arises from the 
ophthalmic nearly opposite to the anterior orbitary 
foramen, through wliich it passes : and after enter- 
ing the cranium is distributed like the other through 
some of the foramina of the cribriform plate to the 
anterior cells of the ethmoid bone, and to tiie ante- 
rior part of the Schneiderian membrane on the sep- 
tum of the nose, to v/hich it sends a considerable 
branch. 

In its course it sends twigs to the frontal sinuses, 
and to the dura mater and its falciform process. 

8. The arteries of the Palpebrx are called Supe- 
rior SiwA Inferior ; ihey leave the ophthalmic near 
the loop or pully of the superior oblique muscle. 
The inferior comes off first; it sends branches to the 
ligaments of the tarsus, the caruncula lachrymalis, 
and the parts connected with the cartilage of the un- 
der evelid. and unites with thelachrvmal arterv near 



Branches of the Ophthalmic Artery. — Carotid. 235 

the external cantlius, forming an arch called the In- 
ferior Tarsal Arch. 

9. The Sii'perior Artery supplies the superior part 
of the orbicularis muscles, the ligament and carun- 
cnla also : and it likewise unites with a twig of the 
lachrymal, and forms the superior tarsal arch. 

Soon after sending off the palpebral branches, the 
Ophthalmic Artery arrives at the internal canthus, 
and then finally divides into two branches, the nasal 
and i\\e, frontal. 

10. The JVasal Branch passes above the superior 
part of the lachrymal sac and the ligament of the eye- 
lid to the nose ; after sending a twig to the frontal 
muscle and the lachrymal sac, it passes down the 
side of the nose and anastomoses with the fascial 
artery. 

11. The Frontal Artery is not so large as the na- 
sal ; it generally divides into three parts. A super- 
ciliary branch vt'hich is principally spent upon the 
eyebrows ; a superficial branch which is spent upon 
the forehead ; and a branch which is distributed to 
the pericranium. 

The INTERNAL CAROTID, soon after parting with 
the ophthalmic, sends off, in a posterior direction, a 
branch to join one from the vertebral artery. From 
its destination this vessel is called the arteria com- 
municans. 

After this it sends off another branch, which is so 
large that it may be considered as a continuation of 
the main trunk : this is called the middle artery of 
the brain, or the Arteria Sylviana. It runs outwards 
nearly in the direction of the fossa Sylvii, which se- 
parates the anterior from the middle lobes of the ce- 
rebrum. In its course it divides and subdivides into 
numerous branches which are spread upon the Pia 
Mater, and finally enter the surface of the brain in a 
very minute state. 



256 Bight and Left Subclavian Arteries. 

The internal carotid then terminates in a branch 
which is smaller than the last mentioned, and from 
its situation is called the Anterior Artery of the 
Brain, or Arteria Callosa. This vessel first inclines 
towards its fellow on the opposite side, and after ap- 
proaching within half an inch of it, forms another 
curve, and runs forward to the anterior part of the 
brain, dividing itself gradually into branches which 
pass in several directions. 

When these anterior arteries are nearest to each 
other, a small transverse branch, which passes at 
right angles, connects them together. This branch 
completes the anterior part of the Circle of Willis^ 
It crosses immediately before the sella turcica and 
pituitary gland, and sends off branches which pass 
to the third ventricle, to the fornix and septum lu- 
cidnm, and also to the pia mater. 

The Anterior Arteries of thte brain also send off 
branches to the optic and olfactory nerves ; to the 
opposite surfaces of the two hemispheres on each 
side of the falx ; to their inferior surfaces, and to the 
corpus callosum. 

They have likewise some branches which anas- 
tomose with those of the middle artery of the brain^ 
and of the vertebral artery. 

The SUBCLAVIAN Arteries. 

The RIGHT SUBCLAVIAN may be considered as the 
continuation of the arteria innominata. This last 
mentioned artery, after leaving the aorta, forms a 
curve or arch, which extends obliquely backwards 
and outwards, over the first rib to the axilla, crossing 
the trachea in its course. At the distance of an inch 
and a quarter, or an inch and a half from its origin, 
it sends off the right carotid, and then, assuming the 
name of Right Subclavian, CQutiuues in the above 
stated direction. 



Tlie Left Subclavian Artery. S5T 

The cord of the curve of this artery, and the cord 
of the curve of the aorta, are not in the same direc- 
tion, but form an angle with each other. 

The position of the left subclavian is some- 
what different from that of the right. Its origin is 
posterior, and, therefore, the direction of the cord of 
its curve is more immediately lateral. The curve or 
arch is also smaller. The situation of the two sub 
clavians as relative to the contiguous parts, is, there- 
fore, somewhat different ; but each of tliem proceeds 
between the anterior and the middle scaleni muscles, 
and when they have arrived at these muscles, their 
respective positions are very similar. 

The anterior and middle scaleni mnscles arise 
from the transverse processes of several of the cervi- 
cal vertebrae, and are inserted into the first rib, one 
before the other, so as to leave a considerable space 
between them. The subclavian arteries pass through 
this space, and before they arrive at it, but when 
they are very near the above mentioned muscles, 
they send off several very important branches in va- 
rious directions, viz. to the cavity of the cranium, to 
the parietes of the thorax, to the thyroid gland, and 
to the lower part of the neck. 

They proceed near to the scaleni muscles before 
they send off any branches ; and it is to be observed, 
that the subclavian veins which correspond with 
these arteries, are anterior to them, for they pass 
before the scaleni muscles, and not between them. 

The INTERNAL MAMMARY Artery 

Goes downwards, from the lower and anterior part 
of the subclavian, along the inner side of the anterior 
scalenus muscle. It proceeds, exterior to the pleura, 
across the cartilages of the true ribs, and near their 
middle ; and, continuing between the cartilages and 
the diaphragm, exterior to the peritoneum, termi- 
Vql. 11. 33 



358 Course and Distribution of the Inferior 

nates on the rectus abdominis muscle, in branches 
which anastomose with those of the epigastric artery. 
In this course it gives branches to almost all the 
parts to which it is contiguous, viz. to the muscles 
and glands at the lower part of the neck ; to the 
thymus gland ; to the parts in the intercostal spaces ; 
to the sternum ; to the mediastinum and pericar- 
dium ; to the diaphragm and to the muscles of the 
abdomen. 

From some of its ramiiications upon the parts be- 
tween the ribs^ small branches go off to the mamma, 
and thereby give a name to the artery. There is 
also a small vessel which is sent off by the mamma- 
ry artery, or by one of its upper branches, which ac- 
companies the phrenic nerve to the diaphragm. 

The INFERIOR THYROID Avtevy 

Arises from the upper side of the subclavian nearly 
opposite to the origin of the internal mammary. It 
passes upwards and inwards, between the carotid 
artery and the spine, to the thyroid gland : then it 
anastomoses with the branches of the superior thy- 
roid on the same sidcj and with those of its fellow 
on the opposite side. 

This vessel sometimes sends off large branches to 
the muscles at the lower part of the neck. 

The VERTEBRAL Artery 

Arises from the upper and posterior part of the sub- 
clavian. It goes upwards and backwards between 
the muscles which lie on the front of the spine, and 
passing under the transverse process of the sixth or 
seventh cervical vertebra, enters into the canal form- 
ed in the transverse processes of the vertebrae. In 
this course, as it proceeds from the third to the se- 
cond cervical vertebra, it inclines outwards laterally, 
and^ in its passage from the transverse process of 



Thyroid and the Vertebral Arteries. 2o9 

the second to that of the first vertebra, it forms a 
considerable curve, the convexity of which has a 
lateral and external aspect. After passing the trans- 
verse process of the Atlas, it is turned suddenly 
backwards, in a groove, and finally passes through 
the great occipital foramen into the cavity of the cra- 
nium. It then proceeds upon the cuneiform process, 
of the occipital bone, under the Medulla Oblongata^ 
and joins its fellow so as to form an acute angle with 
it near the union of the medulla oblongata with the 
pons Varolii. From each of the vertebral arteries^ 
before their union, there generally goes oif a small 
branch called the Posterior Meningeal, which is 
spent upon the posterior part of the dura mater. 

The trunk formed by the union of the vertebral 
arteries is called 

The BASILAR Artery. 

It extends forward near to the anterior part of the 
pons Varolii, where it bifurcates ; but previously 
sends off several branches on each side. The first 
pair go off in a lateral direction, soon after its com- 
mencement, near the back part of the pons Varolii, 
and are spent upon the medulla oblongata, the pons 
Varolii, and the other contiguous parts, and also 
upon the fourth ventricle and the Plexus Choroides 
of that cavity. They are called the Posterior or In- 
ferior Arteries of the Cerehellum. 

Two other lateral branches, which are called the 
Superior Arteries of the Cerebellum, go off from the 
Basilar artery, near its anterior extremity. These 
are principally spent upon the crura of the cerebel- 
lum and cerebrum; upon the cerebellum itself, and 
the contiguous parts. 

S(ton after sending off the last mentioned arteries, 
the Basilar artery divides into two branches, which 
also take a lateral direction, and are of considerable 



260 Jirteries of the lower part of the J\'*eck, 

size. Ill their course outward, these branches are 
curved with their convexity forward. About ten or 
twelve lines from its commencement, each of them 
sends off* a branch called t!ie Srteria CommimicanS} 
which passes directly forward, and communicates 
with the internal carotid, thus forming the arrange- 
ment which is called the Circle of Willis.^ After 
sending off" these arteries, they continue their lateral 
direction, and are distributed principally to the pos- 
terior parts of the cerebrum. These terminating 
branches of the Basilar Artery are called the Paste- 
rior Arteries of the Cerehrum, 

The SUPERIOR INTERCOSTAL tlHery 

Arises from the upper part of the Subclavian, after 
the Vertebral and Thyroid arteries, and very near 
them. It descends by the side of the spine across 
the first and second ribs, near their heads, and exte- 
rior to the great intercostal nerve. It generally forms 
two branches, which are appropriated to the mus- 
cles, &c., in the first and second intercostal spaces, 
and sometimes a small branch is continued to the 
third intercostal space. From each of these branches 
a small vessel proceeds backwards, and is spent 
upon the contiguous muscles, &c. on the back of the 
thorax. The Intercostal Artery also sends a branch 
upwards to the deep seated parts of the neck. 

In addition to the arteries above mentioned, there 
are several others of considerable size which origi- 
nate either directly or indirectly from the subcla- 

* The aneria communicans is also considered as a branch of the 
Internal Carotid. The arrangement here aUuded to is very remark- 
able. As the branches which pass ofFlaterally from the single trunk 
of the Basilar Artery unite to the Internal Carotids, and the Inter- 
nal Carotids are united to each other, there is an uninterrupted 
continuation of artery, which incloses a portion of space of a deter- 
mined form ; but this form resembles an oblong square more than 
a circle. By this connexion blood will pass from any one of the four 
arteries of the brain to all the others. 



Branches that go off in the Axilla. 261 

viAN, and are spent upon the lower portion of the 
neck, and the contiguous parts. These arteries are 
very different in different subjects, especially as to 
their origin. Two of them, which have been called 
the Anterior and Posterior Cervicals, are generally 
distributed to the muscles and other parts which lie 
on the lower portion of the neck anteriorly and pos- 
teriorly. 

A third, which passes transversely on the lower 
part of the neck, is called the Superior Scapular. 

In some cases the two Cervical Arteries arise from 
the subclavian, after the mammary and the thyroid, 
in a common trunk, which soon divides. Very fre- 
quently they go off from the Inferior Thyroid. 
Sometimes one of them goes off from the Inferior 
TJiyroid, and the other from one of the branches of 
the Subclavian.^ 

The Superior Scapular most commonly arises 
with some other artery, and very often from the 
Inferior Tliyroid. It runs transversely outwards, 
within and above the clavicle, and passing through 
the notch in the upper costa of the scapula, divides 
into branches which are distributed to the parts on 
the dorsum of that bone. 

The SUBCLAVIAN ARTERY, iu its progress from the 
aorta to the axilla, forms an arch or curve, over the 
first rib, as has been already observed. The ante- 
rior scalenus muscle is before it, and the great nerves 
of the upper extremity are above it. After passing 

♦ Haller paid great attention to the arterial system, and made 
many dissections with a view to engravings of it, which he pub- 
lished with descriptions, in foho fasciculi. 

These fasciculi have been collected, and, with some other en- 
gravings, form a large volume, entitled icones anatomic/k, Avhich 
is truly valuable. 

There are some very interesting observations on this work of 
Haller's, and also on these arteries, in a description of the 
ARTERIES, by Dr. Barclay of Edinburgh, which 1 have read with 
advantage, as well as a work on the muscles bv the same author 



262 Branches that go ojf into the Jlocilla. 

between the scaleni it descends upon the first and 
second rib into the axilla. The nerves which were 
above, descend with it : at first they are necessarily 
exterior to it, but they form a plexus which the 
artery enters into, so as to be partly surrounded by 
them. This course of the artery is obliquely under 
the clavicle, and behind the pectoral muscle. In 
the axilla, the vessel and nerves which surround it 
are placed between the tendons of the pectoralis and 
the latissimus dorsi muscles. Here the artery takes 
the name of axillary, and sends off several impor- 
tant branches. 

The jjrmcijjal branches that go off from the axil- 
lary artery are distributed. 

1st. Anteriorly, to the pectoral muscle, and the 
parts on the anterior surface of the thorax. 

Sd. Posteriorly, to the muscles which are on the 
scapula and contiguous to it ; and 

3d. To the parts which are near the upper extre- 
mity of the OS humeri. 

Anterior Branches. 

The arteries which go to the pectoral muscle, &c* 
are very various in different subjects, both as to their 
number, origin, and size. 

They have also been called by different names, as 
Thoracicse, Mammariae Externx, ^e. 

There are almost always three of them, and very 
often more ; one of them, which is called by several 
authors the Ac7'077iialis^ proceeds towards the end of 
the clavicle, and generally passes out at the interval 
between the deltoid and the pectoral muscle, send- 
ing various branches to the contiguous parts ; the 
largest of its branches often passing in the direction 
of the interstice between those muscles. 

Another of these arteries, which is called Superior 



Branches that go off in the Axilla. 263 

Thoracic, is generally very small : it often is a branch 
of the above mentioned Jlcromialis. 

There is very often to be found here an artery 
called the Inferior Thoi'acic, or the External Mam- 
mary, which is of considerable length, although its 
diameter is not very great. This artery originates 
near the two last mentioned, and sometimes from the 
Acromialis. It often extends downwards as low as 
the sixth rib, and send branches to the anterior part 
of the thorax, to the mamma, and the other contigu- 
ous parts. Many of the small branches of this ar- 
tery anastomose very freely with those of the internal 
mammary. 

There are always small arterial branches in the 
axilla, which ramify upon the glands and adipose 
matter always existing there. They often arise by 
one common trunk^ which is called the Jlxillary 
Thoracic. 

Posterior Branch. 

One large artery is commonly sent to the muscles 
on the scapula, which is called the Scapular, the 
Common Scapular, or the Internal Scapular. It 
commonly passes off from the axillary after the tho- 
racic arteries, and supplies the muscles on both sur- 
faces of the scapula. This large vessel passes down- 
wards a short distance in the direction of the inferior 
costa of the scapula, and soon sends oif a branch 
that winds round to the dorsum of the bone, to be 
distributed to the infra spinatus and the contiguous 
muscles, which is called the Borsalis Scapulx. The 
main trunk then inclines to the subscapularis muscle, 
and generally divides into two branches, whicli are 
distributed to the subscapularis, teres major, latissi- 
mus dorsi, &c. 

Sometimes the Scapular artery divides into two 
branches before it sends oif the dorsal. In this case 



264 Humeral Artery, 

the last mentioned artery §oes off from one of those 
branches. 

Branches near the Os Humeri, 

The arteries which are near the body of the os 
humeri at its upper end, are generally two in number, 
and denominated the Anterior and Posterior Circum- 
flexx. Sometimes they arise separately, and some- 
times in a common trunk from the axillary artery. 
Frequently one of them arises from the scapular. 

The Anterior Cireumfiex passes between the 
united heads of the biceps and coraco brachialis 
muscles and the body of the os humeri, at a small 
distance below its head. It sends branches to the 
capsular ligament, the periosteum of the os humeri, 
the membranes of the groove for the long head of the 
biceps, the upper portions of the biceps and coraco 
brachialis, and some contiguous muscles. 

The Posterior Circumflex proceeds between the 
subscapularis and teres major muscles, and contin- 
ues between the os humeri and the head of the triceps 
and the deltoides. It is distributed to the muscles 
and parts about tlie joint, especially the deltoides. 

These arteries surround the os humeri, and the 
small branches anastomose with each other. The 
Posterior Circumflex is much larger than the An- 
terior. 

The great artery of the arm proceeds from the 
axilla to the elbow ; and, during this course, is gene- 
rally denominated 

The HUMERAL Artery.^ 

Its direction is iniiuenced by the position of the os 
humeri. When the arm hangs down, with the palm 
of the hand presenting forward, this direction is 

* It is also called Brachial Artery by several writers. 



Branches of the Humeral Artery, 265 

!«omewhat spiral. The situation of the artery is on 
tl>e inside of the biceps muscle, and between that 
muscle and the triceps extensor. It also continues 
very near and on the inside of the tendon of the bi- 
ceps, and under the Aponeurosis which proceeds 
from that tendon. In consequence of the spiral or 
oblique course of the artery, its direction would be 
from the inside of the tendon of the biceps to the ra- 
dial side of the fore arm, but soon after it passes 
across the joint of the elbow, it divides into two 
branches : one which preserves, for some distance, 
the direction of the Main Trunk, is called the Ra- 
dial artery : the other, which inclines obliquely 
downwards and towards the ulna, is the Common 
Tritn/£r of the t7/?zar and Interosseal arteries. 

During; this course, the humeral artery sends off 
several branches to the muscles and other parts on the 
OS humeri. The largest of them is denominated the 
Profunda Humeri, or Spiralis. This artery very 
often arises as high as the insertion of the latissimus 
dorsi, and passing between the heads of the triceps 
extensor muscle, proceeds downwards under that 
muscle, in a spiral direction, towards the external 
or radial condyle. It sends several branches to 
the triceps and the contiguous muscles, and one con- 
siderable branch, which is generally called the Pro- 
funda Minor, to the parts contiguous to the internal 
condyle. The ramifications of these branches near 
the condyle frequently anastomose with small branch- 
es of the radial and ulnar arteries.* 

A small branch^pquently arises from the Hume- 
ral artery, at a ^rort distance from the Profunda 
Humeri, which sends a ramification to the medullary 



♦ The Profunda sometimes originates from the scapular, or one 
of the circumflex. The profunda minor sometimes has a distinct 
and separate origin, lower down than the otlier. 

Vol. 11. 31 



266 Madial Artery. 

foramen of the os humeri. This vessel is, therefore, 
denominated Arteria JS'utritia. 

There are very often several anastomoses between 
the branches of the humeral artery, which originate 
above the elbow, and certain branches of the Radial 
and Ulnar arteries, which are called from their di- 
rection recurrents. Among these arteries there is 
generally one of considerable size, which proceeds 
across the elbow joint near the internal condyle. 
Sometimes this is the ulnar recurrent, which goes up 
to anastomose with the branches of the profunda; 
but more frequently it is a separate branch of the 
Humeral artery, which goes off a little above the 
elbow, and passes across the articulation, near the 
internal condyle, to anastomose with the branches of 
the ulnar artery. This artery is denominated the 
Anastomotica. 

There are often other branches sent off by the 
HUMERAL artery 5 but they are commonly small, and 
very irregular. 

The two great ramifications of the humeral arte- 
ry on the fore arm have very different directions. 
The Radial artery preserving the course of the main 
trunk, while the Common Trunk of the Ulnar and 
Interosseal projects from it in a direction downwards 
and towards the ulna, passing under the pronator 
teres, &c. 

The radial Artery, 

Passing over the pronator teres muscle, proceeds 
between the supinator radii longus and the flexor 
carpi radialis, very near to the lower end of the ra- 
dius, without changing its direction materially, being 
deep seated above and superficial below ; it then 
alters its course, and, passing under the tendons of 
the extensors of the thumb; to the back part qI tb^ 



Course and Ramifications of the Radial Artery, 267 

radius, it continues between the metacarpal bones of 
the thumb and of the index finger, when it divides 
into three branches. 

In this course it gives off but few branches. The 
first is the Radial Recurrent, which passes upwards 
and towards the external condyle, and frequently 
anastomoses with the ramifications of the profunda 
humeri. 

The branches which it sends off between the 
origin of the recurrent and the lower end of the 
radius are generally very small, and distributed to 
the parts immediately contiguous to the artery.— 
Before it turns under the tendons of the extensors of 
the thumb, it sends a branch over the wrist towards 
the root of the thumb, from which proceeds a branch 
to anastomose with the volar branch of the ulnar | 
and another, not so large, which is frequently con- 
tinued on the radial or external side of the thumb^ 
very near to its extremity. While the radial artery 
is under the aforesaid tendons, it sends off small 
branches to the back of the wrist and back of the 
hand, and often to the back of the thumb. Those 
which are distributed to the wrist and back of the 
hand, generally anastomose with the small branches 
of the ulnar and interosseal arteries. 

The three branches into which the radial artery 
divides between the metacarpal bones of the thumb 
and index are, 1st. a bra^nch to the external side of 
the index ; 2dly, a branch to the thumb, that some- 
times divides into two which pass up on the anterior 
or volar surface, and sometimes continues, without 
much diminution, on the internal side of the thumb, 
near to the end of the last phalanx ; and, 3dly, a 
branch, called Falmaris Profunda, whicii dips down 
into the palm of the hand, and, proceeding in con- 
tact with the metacarpal bones, under the flexor 
tendons, &c. forms an arch which extends acroie the 



268 Origin of the Ulna?' and Inferosseal Arteries. 

hand, and often terminates by anastomoses with 
another arch, soon to be described, which is formed 
by the ulnar artery. 

This flexure, which is denominated Jlrcus Pro- 
fundus j sends off branches of a very small size, which 
are distributed to the bones, ligaments, muscles, &c. 
contiguous to it. 

The COMMON TRUNK of the ULNAR and INTEROSSEAL 

Arteries 

Passes ilnder several of the muscles which originate 
from the internal condyle, and between the flexor 
sublimis and the flexor profundus. Before the 
Ulnar Recurrent goes off from this vessel, the inte- 
rosseal artery often leaves it. This recurrent artery 
passes upwards between the muscles of the internal 
condyle, and distributes branches among them. It 
then passes up in the groove behind the internal con- 
dyle, and anastomoses with tbe branches of the 
tdnastomotica or Profunda Humeri. 

The ulnar and interosseal arteries separate from 
each other at the distance of fifteen or twenty lines 
from the origin of the radial artery, very near the 
commencement of the interosseal ligament. 

The INTEROSSEAL Artery, 

In a majority of cases arises in a single branch from 
the common trunk of the ulnar and interosseal. When 
it does so, the single branch soon sends off the Pos- 
terior Interosseal artery, which perforates the inte- 
rosseous ligament, and passes down on its posterior 
surface, while the main branch continues on the an- 
terior surface of the ligament, and is denominated 
the Anterior Interosseal Artery. In some cases the 
main branch proceeds on the anterior surface as low 
as the upper edge of the pronator quadratus muscle, 
before it sends off the posterior branch. Sometimes 



Course of the Ulnar Artery, 269 

the anterior and posterior interosseals arise sepa- 
rately. In this case the posterior soon perforates the 
ligament. 

The Anterior Interosseal passes down almost in 
contact with the ligament, and gives branches to the 
contiguous parts in its course. It generally perforates 
the interosseous ligament near the wrist, and sends 
oif many small branches to the back of the wrist and 
hand, which anastomose with the small branches of 
the radial and the posterior interosseal arteries. 

The Posterior Interosseal soon gives off a recur- 
rent or anastomosing branch, and then proceeds 
downwards towards the wrist, sending branches in 
its course to the extensor muscles and tendons. 

This vessel sometimes divides into two branches. 

The ULNAR Artery. 

The Ulnar artery proceeds among the muscles 
obliquely downwards, and is not superficial until \i 
has arrived within three or four inches of the carpus : 
it then continues towards the hand, sending off 
very small branches in its progress. It passes over 
the annular ligament at the wrist, and winds round 
the pisiform bone : here it is supported by a delicate 
ligament, which seems to lie upon it : from this it 
passes upon the palm of the hand, tinder the aponeu- 
rosis palmaris, and over the tendons of the flexors 
of the fingers. When thus situated, it forms, in 
perhaps a majority of subjects, an arch or bow, 
called *3rciis Sublimis, which extends across th& 
palm of the hand, from the ulnar towards the radial 
edge, and, after sending branches to the fingers, &c. 
from its convex side, terminates near the root of the 
thumb, by anastomosis with that important^ branch 
of the radial artery, which passes up on the inside 



270 Digital Arieries. 

,»; of tTie thumb. The »lrcus Suhlimis almost always 
sends off small branches to the integuments, &c. on 
the palm of the hand. It often sends off, near the 
root of the metacarpal bone of the little finger, a 
branch which passes between the flexor tendons and 
the metacarpal bones, and anastomoses with the Ar- 
eas Profundus. It then generally sends off a branch 
to the inner or ulnar side of the little finger ; and af- 
terwards three branches in succession, which pass 
from its convex side towards the angles formed by 
the fingers. These are called 

The Digital Arteries. 

When they have arrived near to the heads of the 
first phalanges of the fingers, each of these arteries 
divides into two branches, one of which passes along 
the side of one of the fingers to its extremity, and the 
other on the opposite side of the next finger : and in 
this way they pass on the sides of all the fingers, 
except the inside of the little finger and the outside 
of the index. 

These branches of the digital arteries are called 
Digito Radial and Digito Ulnar arteries, according 
to the sides of the fingers on which they are placed. 
They are situated on the angle, if it may be so term- 
ed, which is formed by the anterior and lateral sur- 
faces of each finger. In their course from the basis 
to the extremity of the finger, they send off very 
small transverse branches, which anastomose with 
each other, especially near the other. Some trans- 
verse branches are observable on the posterior as 
well as the anterior surfaces. Near the extremity 
of each finger, beyond the insertion of the flexor 
tendon, the extremities of these arteries ramify mi- 
nutely. Some of these small branches go to the 
skin, aftd others anastomose with their fellows of 



Bronchial Artery. 27 1 

the opposite side. Some also go to the back of the 
fiugers.* 

SECTION III. 

Of the Branches ichich go off between the arch and 
the great bifurcation of the AORTJL, 

PART I. 

In the Cavity of the Thorax, 

THE aorta sends branches to the Lungs, to the 
oesophagus, and to the parietes of the thorax. 

The BRONCHIAL J.rteries 

Are the vessels which go from the aorta to the rami- 
fications of the trachea, and the substance of the 
lungs. They are not large, and are very irregular 
as to number and origin. 

In a majority of cases the right lung is supplied, 
in part, by a branch from the first aortic intercostal 
of that side ; while the left lung receives two or three 
branches from the aorta directly. In some cases a 
large vessel arises from the aorta, which divides into 
two branches, one of which goes to each lung. 



• The distribution of the radial and ulnar arteries in the hand, is 
very different in different subjects. 

Upon examining a large number of injected preparations in Phi- 
ladelphia, it was found that, in a very small majority of them, the 
ulnar artery formed an arcus sublimis, whose branches extended as 
far as the ulnar side of the index, and sometimes beyond it. 

That, in near a third of the preparations, the ulnar artery rami- 
fied without forming an arcus, and supplied only two of the digital 
branches, viz. the first two on the ulnar side. In such cases the 
radial artery generally made up the deficiency of the ulnar, but in 
a few instances the interosseal was extended on the palm of the 
hand, and supplied the radial side of the middle finger and the cor- 
responding side of the index. 

In a few instances also the ulnar artery was still more deficient, 
and the radial was proportionally extended. 



272 Oesophageal and Intercostal Arteries. 

The Bronchial arteries frequently send small 
branches to the posterior mediastinum^ the pericar- 
dium; &c. 

Injections have shown, that there is a direct com- 
munication between these vessels and the branches 
of the pulmonary artery. 

The Oesophageal Arteries 

Are very small vessels, which generally arise from 
the aorta, but sometimes are branches of the bron- 
chials or intercostals that are spent upon the oeso- 
phagus. They occur in succession, and sometimes 
are five or six in number. They also send twigs to 
the contiguous parts, and the lowermost often de- 
scend to the stomach. 

TJie Inferior Intercostals 

Are the arteries which proceed directly from the aorta 
to the parietes of the thorax. Their name is derived 
from their position between the ribs. They are ra- 
mified on the intercostal muscles and ribs, and on 
the pleura and some of the contiguous parts. They 
are called Infeinor or Aorta Intercostals^ to distin- 
guish them from the superior intercostals, which are 
derived from the subclavian artery. Their number 
varies from ten to eight, according as the superior 
intercostals are more or less numerous. 

They originate in pairs on the posterior surface of 
the aorta. The uppermost of them pass obliquely 
upwards, and the lowermost nearly in a horizontal 
direction, to the lower edges of those ribs to which 
they are appropriated. They meet the rib near its 
tubercle, or place of junction with the transverse 
process of the vertebra, and then proceed forward, 
between the internal and external intercostal mus- 
cles, in a superficial but large groove, which is ge- 
nerally to be found on the interior margin of the 



Intercostal Arteries. 273 

lower surface of the rib.* There is necessarily a 
•difference in the length of the right and left intercos- 
tals, owing to the position of the aorta, which is 
rather on the left of the spine. In consequence of 
this circumstance, the OBsophagus is anterior to, and 
also in contact with those of the right side. 

They generally send off an important branch, call- 
ed the Dorsal, which arises near their origin, and, 
passing backwards, sends ramifications to the mus- 
cles of the back. From this dorsal branch also 
proceeds a ramification, which enters the spinal 
cavity, and is spent upon its membrane and upon the 
medulla spinalis. 

After the Intercostals, in their progress forward, 
have passed beyond the middle of the ribs, they send 
off a branch, which generally proceeds very near to 
the upper side of the lower rib. The main trunk 
generally leaves the lower edge of the rib when it 
has arrived within one third of the length of the bone 
from its anterior extremity. It then generally di- 
vides into several branches, some of which are spent 
upon the pleura, and others on the intercostal and 
the contiguous muscles. 

According to the situation of the different inter- 
costals, some of their ramifications communicate with 
those of the internal and external raammaries, of the 
phrenic, the lumbar, or the epigastric arteries. 



See Vol.1, page 95, 



Vol. it. m 



274 Cavity of the Jihdomen. 



PART IL 

In tJie Cavity of the Abdomen. 

The AORTA passes into the cavity of the abdomen 
between the crura of the diaphragm, as has been al- 
ready mentiooed. In its course from the crura to its 
great bifurcation, it sends off one pair of small arte- 
ries, called Phrenic, to the diaphragm. Three sin- 
gle arteries, the cceliac, the superior, and the in- 
ferior mesenteric, to the viscera of the abdomen. 
A pair of large arteries, the emulgents, to the kid- 
neys, with several that are very small to their 
appendages ; as the Spermatices, Capsular, the Ui^e- 
teric, and the Mipose. In addition to these, there is 
one pair of small arteries that go to the testicles, or 
to the ovaria and the uterus, and four or five pair, 
called Lumbar Arteries, that go off laterally, like 
the intercostals, to the parietes of the abdomen, and 
to the muscles, &c. on the back, which are contigu- 
ous to them. 

XJie PHRENIC Arteries 

Are ramified on the concave surface of the dia- 
phragm, and are almost always two in number ; they 
are denominated right and left from their position. 
They commonly originate separately from the aorta, 
but sometimes they arise in a common trunk which 
soon divides. In some instances they are derived 
from the cosliac. in a few cases, the aorta furnishes 
one, and the cceliac the other. Each of the phrenic 
arteries commonly crosses the crus of the diaphragm 
on its respective side, and proceeding laterally, in a 
circular direction, often ramifies so as to form an in- 



Distribution of the C celiac Artery. 215 

ternal and external branch. Each of them gene- 
rally sends branches to the cardia or cesophagus, to 
the glandulse renales, and other contiguous parts. 

The CCELIAC drterij 

Is the first great branch given off by the aorta in 
the abdomen, and is distributed almost entirely to 
the stomach, the liver, and the spleen. It projects 
from the anterior part of the aorta so as to form a 
right angle with it, and is of course nearly horizon- 
tal, when the body is erect. 

The main trunk of this great artery is so remark- 
ably short, that it has been compared to the stump 
of a tree : for at the distance of half an inch from its 
origin, it generally divides into three branches, 
which pass to the stomach, the liver, and the spleen, 
and are, therefore, denominated the Gastric or Co- 
ronary, the HEPATIC and the splenic arteries. 

The first mentioned branch may be called 

THE SUPERIOR COUONARY OR GASTRIC ARTERY, 

To distinguish it from other branches, soon to be de- 
scribed. It is commonly in the centre of the three 
great ramifications of the cceliac, and is also the 
smallest of them. It proceeds from its origin to the 
upper orifice of the stomach or cardia, and continues 
thence along the lesser curvature of that viscus, un- 
til it approaches near to the pylorus. In this course 
it sends branches to the oesophagus, which frequently 
inosculate with the oesophageal arteries. It also fur- 
nishes branches to the cardia, which partially sur- 
round it ; and on this account, the artery has been 
called Coronainj. Some of these last mentioned 
branches are often continued on the great extremity 
of the stomach, and anastomose with those ramifica- 
tions of the splenic artery, called Vasa Brevia. 
It continues on the lesser curvature between the 



276 distribution of 

larainjE of the small omentum, and sends off succes- 
sively branches which pass between tlie peritoneal 
and muscular coats, and are distributed to the ante- 
rior and posterior surfaces of the stomach, communi- 
cating with the branches of the inferior gastric arte- 
ries, soon to be described.* 

THE HEPATIC ARTERY 

Proceeds from the great ramification of the cceliac to 
the transverse fissure of the liver called the Portce, 
in which it generally divides into two branches. In 
this course it very frequently sends off an artery to 
the pylorus, which ramifies about the small extre- 
mity of the stomachj and often inosculates with some 
of the branches of the superior coronary. This 
branch is called the Pylorica, and sometimes it arises 
from the artery next to be mentioned. 

The GASTRICA INFERIOR DEXTRA, 

Which also generally originates from the main 
trunk of the hepatic, but sometimes from one of its 
branches, ft is an artery of considerable size, 
which proceeds along the great curvature of the sto- 
mach, from the pylorus towards the great extremity, 
between the laminae of the anterior portion of the 
omentum, and distributes its ramifications to both 
sides of the stomach, and also to the Omentum. In 
its progress from the liepatic artery to the stomach, 
it sends off branches to the J)uodenu?n, and to the 
right end of the Pancreas. 

The two great hranches into which the hepatic 
artery divides, are denominated right and left, from 
the lobes of the viscus, to which they are respective- 
ly appropriated. The right branch is the largest. — 

• This^arterj' sometimes sends a branch to the liver. When this 
i§ the cas'e, it is always very large. 



. the Splenic Artery. 277 

Before it penetrates the substance of the liver, it 
sends off a branch to the gall bladder, called the 
Cystic Artery. 

The branches of the hepatic artery ramify very 
minutely in the liver, as has been stated in the ac- 
count of that organ. 

The last great branch of the coBliac is 

Tlie SPLENIC Artery, 

Which is generally supposed to be larger than the 
hepatic in adults, although it is less in children. It 
proceeds in a transverse diiectiou from its origin to 
the spleen : its course is not straight, but meandering 
or serpentine. It is situated behind and above the 
pancreas, and passes along the groove in the upper 
edge of that viscus. In its progress, it sends off 
Dianj' small branches, and one that is of considera- 
ble size, to the Pancreas. It also sends one branch 
to the left extremity of the stomach, which arises 
commonly from the main trunk, but sometimes fmm 
the ramifications, which are soon to be mentioned. 
This branch, which is called 

The GASTRICA INFERIOR SINISTRA, 

Is sometimes, but not often, very large : Its course 
is from left to right. It is situated between the 
laminae of the anterior portion of the omentum. It 
sends some small branches to the omentum, and 
others which are larger and more numerous, to both 
sides of the stomach. Some of these last mention- 
ed anastomose with the ramifi( ations of the gaslrica 
dextra, which come from the hepatic. 

\V hen the splenic artery approaches near to the 
spleen, it divides into four, five, or six branches, 
each of which penetrates into that viscus by a dis 



278 Distribution of the Superior Mesenteric 

tinct foramen, and then ramifies in the manner de- 
scribed in the account of the structure of the spleen.* 
Either from the splenic artery, or from these ra- 
mifications, four or five branches pass to the large 
extremity of the stomach, and ramify there, commu- 
nicating with the vessels already described. These 
arteries have received great attention from physiolo- 
gists, and are denominated Vasa Brevia. 

The SUPERIOR MESENTERIC, 

Which is the second great branch given off in the 
abdomen by the aorta, is not very different in size 
from the copliac, and originates about half an inch 
below it. It is distributed to the small intestines ; 
to that portion of the great intestine, which is situated 
on the right side of the abdomen ; and to the arch of 
the colon. From its origin it proceeds downwards, 
under the pancreas, and over the lower portion of the 
duodenum, to the commencement of the mesentery. 
When it has arrived between the laminae of that mem- 
brane, it descends in a direction which corresponds 
with that of the root of the mesentery,* and forms a 
gentle curve, with its convexity directed towards the 
intestines. It necessarily diminishes as it descends, 
and generally terminates by anastomosing with one 
of its own branches. — This great artery sends off 
some very small ramifications to the pancreas and 
the duodenum, while it is in their vicinity. It also 
sends two or three branches to the transverse part of 
the colon, to the right portion of the colon, to the be- 
ginning of the great intestine, and the contiguous 
portion of the ileon. These branches are commonly 
termed the Colica Media, Colica Dextra, and Ileo 

* It frequently happens that the splenic artery divides only into 
two or three branches, and they subdivide so as to form five or six, 
which penetrate the spleen. 

t See Vol. II. page 115. 



and the Inferior Mesenteric Arteries. 279 

Colica. From the convex side of the curve, the 
SUPERIOR MESENTERIC sends off the important 
branches which pass between the laminae of tlie me- 
sentery, and supply the Small Intestines. These 
branches are numerous, and many of their ramifica- 
tions anastomose with each other so as to form 
arches. From these arches go oft' other branches, 
which anastomose a^ain with some of similar origin ; 
and this process is repeated successively several 
times, so that a net-work of blood vessels seems to 
be formed on the mesentery. From the mesentery 
the small ramifications are continued in great num- 
bers to the intestines. Some of them anastomose 
with each other on the coats of the intestine ; but an 
immense number of minute arteries are continued to 
the villous coat, so that, when they are successfully 
injected, the surface of that coat appears uniformly 
coloured by the injected.* 

The IJVFEBIOR MESEA'TERIC Artery 

Does not go off from the aorta next in order after the 
superior mesenteric, but succeeds it immediately on 
the intestines, and continues the arterial ramifications 
to the left portion of the colon, to which the branches 
of the superior mesenteric do not extend. 

This artery arises between the origin of the emul- 
gents, and the great bifurcation of the aorta, and pro- 
ceeds downwards, inclining to the left, but keeping 
near to the aorta. There are generally three branches 
distributed to the left portion of the colon, which arise 
from this artery, either separately, or by a common 
trunk which soon divides. It frequently happens, 
that one of these arteries arises separately, and two 
by a common trunk. These are called the Left 

* See the account of the termination of these arteries, at page 110 
of this volume. 



280 Emulgent Ctnd Capsular Jirteries. 

Colic arteries ; and are also sometimes denominated, 
from their position, Superior, Middle, and Inferior, 
The Superior generally anastomoses with that 
branch of the superior mesenteric, which is called 
Colica Media, and forms a remarkable arch, called 
the Great Mesocolic Arch. The ramifications of the 
other branches frequently anastomose with each 
other, and are finally spent upon the left portion of 
the colon. 

The main trunk, diminished by sending off these 
branches, but still of considerable size, runs down- 
wards on the posterior part of the intestine rectum, 
between that intestine and the sacrum, where it often 
divides into two-branches, which continue near to 
the termination of the rectum. From them proceed 
many ramifications that are spent upon the rectum. 
Some of these ramifications anastomose with each 
other, and others with the ramifications of the hse- 
morrhoidal artery, soon to be mentioned. 

The EMULGENT or llENAL Arteries 

Are the large vessels which pass from the aorta to 
the kidneys. They arise between the superior and 
inferior mesenteries, one on each side ; and proceed 
in a direction which is nearly rectangular to the 
aorta. The right emulgent artery is necessarily 
longer than the left, and it generally passes behind 
the vena cava. When they approach near the con- 
cave edges of the kidneys, each emulgent commonly 
divides into three or four branches, which pass into 
the fissure of that organ, and ramify in the manner 
described in the account of it. Sometimes two arte- 
ries proceed from the aorta to the kidney : but this 
is not a frequent occurrence. 

The Capsular Arteries 
Are the small vessels which pass to the glandula* 



Adipose and Spermatic Arteries. 281 

renales. There are almost always several of them 
appropriated to each gland. They often arise on 
each side from the coeliac artery, the aorta, and the 
eraulgent. -^ 

The Adipose Arteries 

Supply the adipose substance surrounding the kid- 
neys. — There are several of them on each side, and, 
like the last mentioned arteries, they are very small, 
and arise from several sources as well as the aorta. 
The testicles and ovaria are supplied by the 

Spermatic Arteries, 

Which are very remarkable for their great length 
and small diameter. In a majority of cases these 
vessels arise from the anterior surface of the aorta, 
a little below the eraulgents : but it often happens 
that the left spermatic arises from the emulgent on 
that side. They also sometimes arise from other 
neighbouring arteries. It has been observed when 
they arise from the aorta, that the origin of one of 
them is generally higher than that of the other. 

They pass downwards, so as to form an acute 
angle with the aorta, and proceed behind the perito- 
neum, and before the psoas muscle and ureter. While 
this artery is in contact with the psoas muscle, it 
meets with the ramifications of the spermatic vein, 
and, in its progress to the abdominal ring, also joins 
the spermatic cord. In this course it sends off some 
very small twigs to the contiguous parts, and others 
that anastomose with similar ramifications from the 
mesenteric, epigastric, &c. Before it arrives at the 
testicle, it divides into several branches, two of 
which generally go to the epididymis, and the 
others penetrate the upper and back part of the 
tunica albugiuea. 

Vol. II. 36 



S82 iSpermatic Arteries. 

The Sjpermatic Arteries in the Female, 

Instead of passing to the abdominal ring, proceed 
between the laminjB of the broad ligaments, and 
send branches to the ovaria, which, in some cases, 
may be traced to the vesicles. They also send 
branches to the fallopian tubes and uterus, and to 
the round ligaments. Those which are on the op- 
posite sides of the uterus, anastomose with each 
other and with the branches of the hypogastric ar- 
teries. 

The lumbar regions are supplied with arteries, 
•which originate, like the intercostals, from the pos- 
terior part of the aorta between the thorax and pel- 
vis. There are four or five of these vessels on each 
side, and they are denominated 

The Lumbar Arteries. 

They pass between the spine and the psoas muscles, 
and send branches to the spinal cavity, to tlie mus- 
cles of the lumbar regions, and the abdominal mus- 
cles. They anastomose with the internal mammary, 
the epigastric, the circumflex of the ilium, &c. 

A small artery passes off singly from the posterior 
part of the aorta at its bifurcation, which is called 

The Middle Sacral Artery. 

It proceeds down the middle of the sacrum to the os 
coccygis, and sends off lateral branches, which are 
spent upon the contiguous parts, and inosculate with 
the arteriae sacrae laterales. 



General Account of the Internal Iliac. 283 



SECTION IV. 

Of the Arteries which originate at and below the 
Great Bifurcation of the Aorta. 

The PRIMITIVE ILIACS 

Form an acute angle with each other. They proceed 
downwards behind the pcritoneunij very near the 
margin of the pelvis, without sending off any branch 
of importance. At the junction of the sacrum with 
the ossa ilea, they divide into two great branches : 
the INTERNAL ILIAC, or HYPOGASTRIC, which des- 
cends into the pelvis ; and the external iliac, 
which passes under the crural arch to the lower ax- 
tremity. 

ThelJVTEBA'AL ILIAC, or HYPOGASTRIC, 

Is distributed, in part, to the viscera of the pelvis 
and the organs of generation, and also to the large 
muscles exterior to the pelvis : it is, therefore, very 
large, although not quite equal to the external 

ILIAC. 

It has already been mentioned, that in the foetal 
state, this vessel appeared to continue in a curved 
direction from its origin to the lower part of the side 
of the bladder, and from thence to the umbilicus, 
under the denomination of the Umbilical Artery, 
From the convex side of this curve the different 
branches of the internal iliac go off. In the foetal 
state they are very small in proportion to the umbi- 
lical artery ; but as the artery becomes ligamentous, 
these l)ranches increase in size. 

In the adult, the arrangement of these vessel is very 
different. The internal iliac generally divides into 
two 2;reat branches: the G/w/m/, which passes through 



284 Smaller Branches of the Internal Iliac, 

the sacro sciatic notch, and ramifies on the exterior 
and upper part of the os ilium : and t!ie Ischiaticj 
which passes downwards on the outside of the tu- 
berosity of the ischium. 

The first of these large ramifications passes out of 
the pelvis above the pyriform muscle, and the last 
of them below it. Several smaller arteries arise from 
these branches near tlieir origin, or from the main 
trunk of the internal iliac, which are distributed to 
the different parts of the pelvis ; and one important 
branch of the ischiatic, called the Pudicy proceeds 
downward on the inside of the tuberosity of the is- 
chium. 

The first of the smaller branches which the inter- 
nal iliac commonly sends oif, is called the 

** lleo Lumbalis : 

It sometimes arises from the gluteal artery, and 
sometimes from the main trunk of the internal iliac. 
It passes outwards under the psoas muscle, and sud- 
denly divides into two branches. One of them pro- 
ceeds upwards, and is distributed in the lumbar re- 
gion, while the other ramifies on the iliacus internus 
muscle, and is spent on the contiguous parts. 

There are also two or three small arteries called 

Arteria. Sacrce Lateralis, 
Which sometimes arise singly, and sometimes in 
common, from the great trunk. They also occa- 
sionally originate from the gluteal artery. These 
vessels enter the anterior foramina of the os sacrum, 
to be distributed on the cauda equina and the mem- 
branes which invest it. Some of their ramifications 
anastomose with branches of the sacra media and 
other contiguous arteries. 

On the anterior side of the internal iliac, near the 
origin of the above mentioned vessels, a ligament 
which was originally the umbilical artery, goes off 



Smaller Branches of the Internal Iliac, 285 

to the side of the bladder, and continues from thence 
to the umbilicus. Sometimes it continues pervious 
for a short distance, and then small branches pass 
from it to the bladder. 

In the female it also sends small branches to the 
uterus and vagina. 

In addition to these Vesical tdrteries derived from 
the umbilicals, there are other branches distributed 
to the bladder, which arise very differently, in dif- 
ferent subjects, from branches which are soon to be 
described, as the hsemorrhoidal, pudic, &c. 

From the anterior side of the internal iliac, or from 
one of its great branches, an artery often arises which 
passes out of the pelvis through the aperture in the 
margin of the ligamentous membrane which closes 
the foramen thyroideum of the os inuominatumj this 
is called the 

Obturator Artery. 

This vessel, while it is in the pelvis, often sends small 
branches to tlie bladder and its ap^-jendages, and to 
the obturator internus muscle. After it passes out of 
the pelvis, it frequently divides into branches ; some 
of winch are spent on the obturator externus, and 
the contiguous muscles, and others go to the hip 
joint. The origin of this artery is variable. Most 
commonly it arises from the internal iliac, but often 
from the ischiatic, and sometimes from the gluteal. 
In some instances it originates in a way that is par- 
ticularly interesting when the operation for crural 
hernia is to be performed, viz. from the epigastric 
artery^ soon to be described : for in this case the ob- 
turator artery sometimes nearly surrounds the neck 
of the hernial sac* 

• See Astley Cooper's great work on Hernia, Vol. I. 
There is reason to Ijclieve that this position of the artery occuri 
raore frequently than has been supposed. * 



280 Larger Branches of the Internal Iliac. 

A small artery passes from the internal iliac or 
cue of its branches, to the rectum, which is called 
the 

Middle Hemorrhoidal, 
From its situation between the branches which are 
sent to that intestine from the inferior mesenteric, 
and those which go to it from the pudic. This 
artery is spent upon that part of the rectum, which 
is above and in contact with the sphincter. It sends 
branches to the prostate anil vesiculai seminales in 
males, and the vagina and bladder in females. 

In females there is a peculiar artery, 

The Titer ine, 
Which originates either from the internal iliac, near 
the origin of the ischiatic, or from one of its branches. 
It passes between the laminae of the broad ligaments 
to the cervix uteri, and penetrates the texture of that 
organ. The size oi this vessel varies with the va- 
rying size of the uterus. 

The GLUTEAL or POSTERIOR ILIAC Artery, 
One of the two great branches of the internal iliac, 
proceeds exteriorly through the sciatic notch above 
the pyriform muscle, very near the edge of the bone. 
On the outside of the ilium it generally divides into 
two branches, one of which ramifies between the 
gluteus medius and minimus, and the other between 
the medius and maximus. It is principally spent 
upon these muscles, and sends branches to the con- 
tiguous parts. 

The ISCHIATIC Artery, 
The other great branch of the internal iliac, passes 
through the sciatic notch helow the pyriform muscle, 
and proceeds downwards, between the great tro- 
chanter of the OS femoris and the tuberosity of the 
ischium, under the gluteus maximus muscle. Soon 



Pudic Artery. 287 

after its ori£;in, it commonly sends oft' a considerable 
branch, the Arteria Pudica, which also passes 
downwards: it then continues its course as above 
mentioned, and its principal branches are distributed 
to the gluteus maximus and the muscles of tlie upper 
and back ])art of tiie thigh, wliile its smaller 
branches go to the os sacrum and coccyx, and tlie 
contiguous small nuisclcs. 

The ruDicA interna, 

As has been just mentioned, is often a branch of the 
iscbiatic artery, but sometimes originates immediate- 
ly from the internal iliac. It proceeds downwards 
and inwards, divelging from the iscbiatic, and pass- 
ing between the two sacro sciatic ligaments to the 
interior side of the tuberosity of the ischium, whence 
it continues on the inside of the crus of the os ischi- 
um and pubis until it approaches the symphisis, 
when it generally divides into three branches, which 
are spent upon the organs of generation, from which 
circumstance the name of this artery is derived. 

One or more branches from it also pass to the 
lower part of the rectum and sphincter ani, and are 
called the Loiver Hemorrhoidal Arteries. 

In its course it sends oil many small branches to 
the contiguous parts ; one of which, called the Peri- 
neal, leaves it near the transversns perinei, and 
passes between that muscle and the skin, and be- 
tween the bulb of the urethra and the crus of the 
penis, to the scrotum. 

When the Pudic has arrived near the bulb of the 
urethra it sends a branch into it, Avhich is continued 
into the corpus spongiosum urethrae, and ramifies 
there minutely. 

At the symphisis of the pubis, it sends off a se- 
cond branch, which passes to the back of each crus, 
and, proceeding along it, parallel to its fellow, ter- 



§88 External Iliac. — Branches of the External Iliac. 

niinates in the glans penis : in this course it sends 
branches to the elastic coat, to the integuments, and 
to the prepuce. This vessel is called the Arteria 
Dorsalis. 

The main trunk of the pudic artery then penetrates 
the corpus cavernosura, and proceeds through it in 
a straight direction. Its ramifications appear to be 
distributed through the internal structure of the cor- 
pus cavernosum, and some of them extend through 
the septum to the other side, while others pass to the 
corpus spongiosum urethrse. 

The EXTERNAL ILIAC, 

The great artery of the lower extremity, appears 
soon after birth, like a continuation of the primitive 
iliac, and proceeds al0ng the brim of the pelvis be- 
hind the peritoneum, to Poupart's ligament or the 
crural arch, under which it passes. 

The psoas muscle is at first in contact with it on 
the outside, and the internal iliac vein on the inside. 
As it passes under Poupart's ligament, it is imme- 
diately anterior to the psoas and iliacus internus 
muscles where they arc united, and the crural nerve 
is exterior to it. Before it arrives at the lower edge 
of Ponpart's ligament, it sends off 

Tilt Epigastric Artery, 

Which arises on its internal side, and proceeds 
downwards and inwards about half an inch, then it 
turns upwards and inwards, and continues in that 
direction for a small distance, after which its course 
is less oblique. It passes between the peritoneum 
and the abdominal muscles, behind the spermatic; 
cord, and the round ligament in females. 

It generally changes its oblique direction after 
passing about two inches^ and then proceeds in con- 



General Account of the Femoral Artery. 289 

tact with the. rectus, and very near its external edge. 
Its ramifications are expended upon the anterior 
parietes of the abdomen ; and, after it has arrived 
as high as the umbilicus, it commonly divides into 
branches, which often inosculate with the ramifica- 
tions of the internal mammary.* 

An artery, which is rather smaller than the 
epigastric, arises nearly opposite to it, but rather 
lower, from the external side of the external iliac. 
It is called 

TTie Circumflex Artery of the Os Ilium, 

And proceeds upwards and outwards to the upper 
margin of the os ilium, along which it continues very 
near to the spine. It is distributed principally to the 
abdominal muscles, to the iliacus internus and the 
psoas, and the parts contiguous. 

T])e artery of the lower extremity, after passing 
under Poupart's ligament, takes the name of 

FEMORAL Artery, 

And proceeds downwards in a direction so spiral^, 
that although it is in front at the upper part of the 
thigh, it is corapU'tely behind at the lower part. It 
sends branches to the muscles of the thigh, as 'the 
aorta does to the viscera of tne abdomen, viz. by a 
few large vessels which extend and ramify to a great 
distance among them. 

The situation of the abductor muscles, and their 
attachment to the os femoris, is such, that the artery 
in this course must necessarily perforate their com- 

* Several respectable surgeons have been taught by experience, 
that when the abdomen is distended by ascites, the position of the 
epigastric artery is so much altered, that it will sometimes be found 
in the middle of the oblique line, which extends from the umbilicus 
to the su])erinr anterior spine of the ilium. 

Vol. IL 37 



290 Branches of the Profunda and the Femoral, 

mon tendon, which it does at the distance of one 
third of the length of the bone from its lower end. 
The aperture in this tendon corresponds precisely 
with the general course of the artery; and before 
the artery enters this perforation, it is on the internal 
side of the bone ; after it has passed the perforation, 
it is on the posterior side of it. After passing 
through the tendon of the abductors, it is denomina- 
ted The Popliteal Artery, and it retains this name 
until it divides. 

It then proceeds downwards, being very near the 
bone, and between the tendons of the flexors of the 
leg, covered by the great nerve of the lower extre- 
mity, and very often also by the vein. After cross- 
ing the articulation of the knee, vi^hen it is between 
the heads of the gastroc nemii muscles, at the lower 
edge of the popliteus muscle, it divides into the an- 
terior tibial and the common trunk of the peroneal 
and posterior tibial arteries. 

The FEMORAL artery, soon after emerging from 
Poupart's ligament, sends off very small branches to 
the inguinal glands, and other contiguous parts. It 
also sends off the 

External Pudlcs 

Which are two or three small arteries that are gene- 
rally spent upon the Scrotum in males and the Labia 
Pudendi in females. 

About two inches below Poupart's ligament, the 
great branch which has been called the muscular 
artery of the thigh, leaves it. This vessel is com- 
monly denominated 

ARTERIA PROFUNDA. 

It arises from the back part of the trunk of the femo- 
ral, and passes downwards and backwards, in a way 
that has been compared to the separation of the in- 



Branches of the Profunda and the Femoral. S91 

ternal iliac from the external. Very soon after its 
origin, it sends off* two branches, which proceed, one 
on the internal, and the other on the external side of 
the thigh, and are called the circumflexa interna and 
externa. It then passes downwards behind the trunk 
of the femoral, and sometimes very near it, on the 
adductor muscles, and finally divides into branches, 
which are called the Perforating. 

The External Circumflex 

Sometimes arises from the femoral, but most com= 
monly is a branch of the profunda, as above stated. 
It passes under the rectus and tensor vaginae femoris 
towards the great trochanter, and generally divides 
into two branches, one of which continues in the 
transverse direction, and sends branches to the up- 
per and back part of the thigh, and the parts con- 
tiguous to the joint ; while the other descends in the 
course of the rectus femoris muscle, and some of its 
ramifications extend near to the outside of the knee. 

The Internal Circumflex 

Is often smaller than the other. It generally passes 
between the psoas and the pectineus muscles, and 
continues round the thigh towards the lesser tro- 
chanter. Its ramifications are expended on the upper 
portions of the adductor muscles and the muscular 
parts contiguous to the lesser trochanter. It also 
sends branches to the articulation. 

The Perforating Jlrteries 

Are two or three ramifications of the profunda, which 
pass through the abductor muscles, and are expend- 
ed upon the flexor muscles on the liack of the thigh. 
Some of the terminating branches of the profunda 
itself are also called perforating arteries. 

The next branch of importance which is sent off 



292 Branches about the Ham. 

by the femoral artery, leaves it before it enters the 
aperture in the tendon of the adductors, and is called 

The Anastomotic Jlrtery, 
This vessel soon inclines downwards. Its ramifi- 
cations extends into the vastus internus muscle; 
some of them follow the tendon of the adductors, 
and ramify about the internal condyle. 

Several small branches go off from the great artery 
soon after it passes through the tendon of the adduc- 
tors, whicii are distributed to the contiguous mus- 
cles. Some of them are also called 

Perforating Arteries. 
Among them is the principal medullary artery of the 
OS femoris. 

In the ham, the great vessel there called 

POPLITEAL, 
generally sends off several small branches. Two of 
them go off on the inside, one above and the other 
below the knee ; and two on the outside in the same 
manner. They are named, from their situation, The 
Superior and Inferior Internal, and The Superior 
and Inferior External Articulary Arteries. 

The Superior Internal artery perforates the ten- 
don of the adductors above the internal condyle, 
and ramifies minutely on the inner side of the joint. 

The Superior External artery passes through the 
lower portion of the biceps above the external con- 
dyle, and ramifies minutely on the outer side of the 
joint. Its superior ramifications anastomose with 
those of the descending branch of the external cir- 
cumflex, while its inferior ramifications communicate 
with those of the corresponding artery below. 

The two inferior arteries originate nearly opposite 
to the middle of the joint, and pass downwards. 

The Inferior Internal artery passes under the 



Arteries of the Leg. 293 

internal head of the gastroc neraius muscle, on the 
posterior and internal side of the head of the tibia. 
Its ramifications communicate with those of the cor- 
responding artery above and of the tibialis antica. 
Below they also extend to the interior of the joint. 

The Inferior External artery passes under the 
external head of the gastroc nemius and the plantaris 
muscle, and continues under the external lateral 
and the capsular ligament. It is distributed on the 
external and inferior part of the articulation, and 
sends also some branches to the interior of the joint. 

There is frequently an azygous vessel, called the 
Middle .Articular artery, whirh arises from the back 
of the popliteal, and is distributed to the posterior 
part of the articulation. 

The POPLITEAL artery, after this, sends off a few 
small branches to the heads of the muscles of the leg, 
and among them one of considerable length, to each 
of the heads of the gastroc nemii. At the under 
edge of the popliteus muscle, it sends off horizon- 
tally a large branch which passes directly forward 
between the tibia and fibula, above the commence- 
ment of the interosseous ligament. After this it con- 
tinues to descend, nearly in the same direction, un- 
der the soleus muscle, behind the tibia ; but before 
it has proceeded further than twelve or fifteen lines, 
it sends off a branch which forms an acute angle 
with it, and approaches near the fibula, along which 
it descends. 

The branch sent off anteriorly, is called the An- 
ierior Tibial artery. 

The main trunk, which continues downwards, is 
called the Posterior Tibial artery ; 

And the branch wijich descends near the fibula is 
called the Peroneal or Fibular artery. 



294 Anterior Artery of the Leg. 



The ANTERIOR TIBIAL Artery, 

After its arrival on the anterior part of the leg, passes 
down close to the interosseous ligament, with the ti- 
bialis anticus muscle on the inside, and the extensor 
communis on the outside, in the first part of its 
course ; and afterwards, with the extensor pollicis 
pedis on the outside of it. It gradually inclines in- 
ternally as it descends, so that a little above the an- 
kle it is upon the front part of the tibia. Tt proceeds 
thence with the tendons of the extensor digitorum 
pedis, under the annular ligament, to the upper sur- 
face of the foot, on which it continues to the inter- 
stice of the first and second metatarsal bones, where 
it descends to anastomose in the way presently to be 
mentioned. 

In this course it sends off, soon after it has arrived 
at its anterior situation, a recurrent branchy which 
is distributed to the heads of the muscles and the 
ligaments of the articulation, and which anastomoses 
with the branches of the inferior articular arteries. 
It also sends off, on each side, many arterial twigs 
to the contiguous muscles, and very frequently one 
branch of considerable size, which passes down near 
the fibula. 

When it has arrived nea,r the end of the tibia, it 
sends a branch on each side, called the Internal and 
External Malleolar. On the top of the foot, among 
several smaller arteries, it sends off a branch under 
the extensor brevis digitorum pedis, which passes 
outwards and forwards, and supplies the muscles, 
&c. on the upper part of the foot. This vessel is 
called Arteria Tarsea. There is also another branch; 
called Metatarsea, which generally arises about the 
middle of the foot, and passes obliquely outward 
and forward;, supplying the contiguous parts. 



Posterior Tibial and Peroneal Arteries. 295 

The Anterior Tibial artery, having arrived at the 
space between the metatarsal bones of the first and 
second toes, bends down to the sole of the foot, but 
previously sends off a branch which passes near the 
external edge of the metatarsal bone of the great toe, 
and divides into two branches, one of which goes to 
the outside of the great toe, and the other to tlie op- 
posite side of the toe next to it. 

The POSTERIOR TIBIAL Artery, 

After sending off the anterior tibial, parts with the 
Peroneal or Fibular, as has been already stated, and 
then continues on the back of the tibia, behind the 
internal ankle, to the sole of the foot. 

The, Peroneal or Fibular Artery 

Is not commonly so large as either of the two other 
arteries of the leg, nor is it so constant. It passes 
down very near the internal edge of the fibula. It 
is in contact, for some distance, with the tibialis pos- 
ticus muscle, and is anterior to the soleus and the 
flexor poUicis longus ; it sends branches to the 
contiguous muscles. After it has passed along two 
thirds of the length of the fibula, it frequently, but 
not always, divides into an anterior and a posterior 
branch. 

The anterior peroneal soon perforates the interos- 
seous ligament, and passing down some distance on 
its anterior surface, continues to the ankle and upper 
surface of the foot. It gives ramifications to all the 
contiguous parts in its progress, and anastomoses 
with some of the small ramifications of the tibialis 
antica. 

The posterior peroneal branch is the continuation 
of the main trunk. It passes behind the external 
malleolus, and ramifies upon the external side of the 
foot. 



296 Jir levies of the Foot. 

The posterior tibial artery passes down, inclinine; 
rather obliquely inwards, between the gastroc ne- 
mius internus, which is posterior to it, and the tibia- 
lis posticus and flexor digitoruui, which are anterior 
to it. Upon the leg it gives off many small branches, 
one of which, termed the Arteria JSTutritia Tibige, 
comes off high up,* and, after ramifying as it de- 
scends, sends a branch to the medullary foramen of 
the tibia. 

At the lower part of the leg the Posterior Tibial 
is situated rather superficially between the tendo 
Achillis and the tibia. It proceeds thence behind 
the internal ankle in a deep situation, covered by an 
annular ligament, and passes between the abductor 
muscle of the great toe and the bones of the tarsus. 
It then divides into two branches — the internal and 
the external plantar arteries. 

The Internal Plantar Artery 

Is commonly much smaller than the other ramifica- 
tion. It passes in the direction of the internal edge 
of the foot, but at some distance fr<»m it, and often 
lies between the aponeurosis plantaris and the ab- 
ductor pollicis. It frequently terminates by anasto- 
mosing with one of the arteries of the great toe, and 
in its course sends off several branches to the conti- 
guous parts on each side of it. 

The External Plantar Artery 

» 
Is the continuation of the main trunk. It proceeds 

outwards and forwards between the short flexor of 

the toes and the flexor accessorius ; and continues 

afterwards between the first of these muscles and the 

abductor of the little toe. At the metatarsal bone of 

* This artery sometimes comes off from the popliteal. 



Arteries of the Foot. 297 

the little toe it begins to curve, and continues its cur- 
vature across the other metatarsal bones to the inter- 
stice between the great toe and the one next to it, 
passing between the tendons of the long extensor and 
the metatarsal hones. At the interstice above men- 
tioned, it anastomoses with the tibialis antica. The 
curvature, thus formed, is called the Arcus Plantaris. 

In this course, the Exte?'nal Plantar sends off 
several branches to the heel and the parts of the foot, 
especially on the external side; the deep seated parts 
of the foot being supplied from the curve. 

Digital branches go off from the curve, as they do 
in the hand, from the curve of the ulnar. There is 
first a small branch to the outside of the little toe 5 
and then three reajulnr branches, which pass to the 
junction of the roots of the four small toes, and di- 
vide, like the digital arteries of the hand, so as to 
send a branch to tlie side of each toe. These digi- 
tal arteries pass between the muscle called Trans- 
versalis Pedis and the metatarsal bones. Near the 
heads of these bones, each of them generally sends 
off two arteries that pass upwards between the in- 
terossei muscles and the bones, and anastomose with 
the ramifications from the top of the foot. 

The External Plantar, soon after sending off the 
the third digital artery, anastomoses with the anterior 
tibial, and then continues to the junction of the root 
of the great toe with tlie one next to it, when it divides 
into two branches, which go to the opposite sides 
of those toes. In its course it also sends a branch to 
the internal side of the great toe. 

Vol. 1L 38 



CHAPTER ni. 

OF THE PARTICULAR DISTRIBUTION OF THE VEINS. 

Anatomists of great respectability have very dif- 
ferent sentiments respecting the best method of de- 
scribing the veins. Some of them, in order to follow 
the course of the circulation, commence with the 
small veins, and proceed to the large trunks which 
are formed by their union. Others begin with the 
great veins that empty into the heart, and proceed 
from them to the small ramifications of the venous 
system, in a direction the reverse of the circulation. 

As the last method is the easiest for the student 
of anatomy, it will be adopted here ; but it must al- 
ways be kept in mind, that the blood flows from the 
small veins into the larger, and not from the latter 
into the former, as the mode of description seems to 
imply. 

The great trunk of the venous system diflPers con- 
siderably from that of the arterial with respect to 
its connexion with the heart ; for it communicates 
with that organ in such a manner that, when viewed 
from before, it appears like two vessels ; one open- 
ing into the upper, and the other into the lower part 
of the right auricle. When viewed from behind, 
it appears like a continued tube, three fourths of 
which are deficient anteriorly ; and to the margin 
of this deficiency the right sinus or pouch of the 
heart is connected. 

In some preparations of the heart, where all the 
great vessels connected with it are much distended 
by the injection, and the pulmonary vessels are in- 



The Veins of the Heart 299 

jected first, the right auricle is so much pressed 
upon from behind, by the vessels which go to the 
right lung, that the direction of the superior and in- 
ferior portions of the vena cava, which thus commu- 
nicate with it, is altered. Each of them is turned 
obliquely forwards, so that it forms an angle with 
the other. This occasions them to appear more like 
distinct vessels than they otherwise would do. 

The above mentioned portions of the great veins 
are denominated the Superior ov Descending, and the 
Inferior or Ascending Vena Cava; as if they were 
perfectly distinct and unconnected with each other. 

The CORONARY Veins, 

Which are exclusively appropriated to the heart, 
may be considered here, as they are not included in 
the general arrangement of the veins. 

The great vein of the heart begins at the lower 
part of the right auricle, very near to the septum, 
which divides the two auricles. It soon proceeds to 
the left, in a circular direction, surrounded with adi- 
pose matter, in the deep groove which exists between 
the left auricle and the left ventricle. It continues 
between the auricle and ventricle, until it is imme- 
diately over the septum, which divides the two ven- 
tricles. Here its direction changes, and it proceedsf 
to the apex of the heart, where its small ramifications 
anastomose with others soon to be described. In its 
course round the basis of the left ventricle, it sends 
off several branches, one of which is considerable, 
that proceed from the basis towards the apex of the 
heart, ramifying on the surface of the left ventricle. 

A second vein, much less than the first, appears 
to proceed from the great vessel at its commence- 
ment,* and continues on the lower fiat surface of 

• It often opens into the auricle by a separate orifice. 



300 Superior Vena Cava and its Great Branches. 

the heart, between the two ventricles, to the apex, 
accompanied by a branch of the right coronary ar- 
tery. This has been called the Middle Vein of the 
lieart. 

In addition to these there are several veins which 
begin at the right auricle, and extend on the surface 
of the right ventricle towards the apex of the heart. 
These have been called the Anterior Veins. 

SECTION I. j 

Of the SUPERIOR or DESCENDING VENA CAVA, 

and the, Veins which communicate with it. 

This great vessel proceeds upwards from the 
superior and posterior part of the right sinus or 
pouch of the heart ;* and a portion of it is so involved 
by the pericardium, that it seems to be included in 
that sac, as the heart is in this situation. It is some- 
what anterior as well as to the right of the aorta. It 
continues above the pericardium, adhering to the 
right lamina of the mediastinum, and rather inclining 
forward. When it is as high as the lower margin 
of the upper rib, it sends off a very large branch, 
which conveys the venous blood of the left arm and 
the left side of the head and neck. This large vein, 
which is very important, both on account of its size 
and its situation, proceeds in a transverse direction 
within the sternum, almost in contact with and but 
little below the upper and internal margin of that 
bone. Immediately behind or within the origin of 
the left steruo-mastoid muscle, it divides into the 
left subclavian, which preserves a transverse course, 
and the left internal jugular, which proceeds to the 
cavity of the cranium by the foramen lacerum. 

After sending off this transverse branch to theleft^ 

* See the description of the heart, in p^ge 51, of this volume 



Fena ^zygos. 301 

the great vein continues upwards and behind the 
right sternomastoid muscle, and there sends oflF, 
nearly at right angles, tlie right subclavian vein. 
After it has parted with this vein^ it takes the name 
of Internal Jugular, and continues to the right fora- 
men lacerum, in the basis of the cranium. The 
superior vena cava is, therefore, principally formed 
by the union of the subclavians and internal jugulars 
from each side of the body. 

Immediately after the superior cava rises above 
the pericardium, before it divides as above stated, it 
sends off, from its posterior part, a large vein which 
is single, and therefore called 

VENA AZYGOS. 

This vessel projects backward above the right 
pulmonary artery and right branch of the trachea, 
and then curves downwards behind them. It pro- 
ceeds down the spine to the right of the aorta and at 
a small distance from it, into the abdomen, between 
the crura of the diaphragm, and sometimes between 
some of the portions of that muscle, which are at- 
tached to the dorsal vertebrae. In the abdomen it 
often anastomoses either with the lumbar veins or 
the vena cava. 

The azygos frequently sends off several small 
veins from its curvature to the contiguous parts, and 
also the right Bronchial Vein, which passes along 
the ramifications of the trachea into the substance of 
the lungs.* In its course downwards it gives off 
branches to the oesophagus, some of which are con- 
siderable. 

The Inferior Intercostal Veins originate directly 
or indirectly from the azygos. In some cases there 
is no Superior Intercostal on the right side ; and then 

♦ This bronchial vein sometimes arises from the superior cava. 



302 Inferior Intercostal Veins. 

the two or three uppermost of the right intercostals 
are also derived from the azygos ; and often origi- 
nate from it by a common trunk, which soon divides. 

Most commonlj^ithe ten inferior intercostals on the 
right side proceed directly from the azygos, and ac- 
company the intercostal arteries. Their posterior 
branches pass into the vertebral cavity, and commu- 
nicate with the veins which are there. 

About the sixth or seventh rib, the vena azygos 
frequently sends off a branch to the left which de- 
scends on the left side of the vertebrae, and sends off 
those Left intercostal veins which are below its ori- 
gin. It passes through the diaphragm with the aorta, 
or to the left of it, and anastomoses either with the 
azygos itself, or in a way which is analogous to the 
anastomosis of that vessel. 

The Vena Azygos may be regarded as the great 
trunk of the veins of the parietes of the thorax, which 
are thus collected, because they could not with con- 
venience pass singly to the vena cava, as the arteries 
do to the aorta. 

Soon after sending off the vena azygos, the Supe- 
rior Cava sends oft' the great transverse branch 
above mentioned. From this it continues upwards 
but a short distance, when it divides, behind the 
right sterno-mastoid muscle, into the right subcla- 
vian and right internal jugular. 

The branches of the superior cava, which thus 
intervene between the great trunk and the subdi- 
visions behind the sterno-raastoid muscles, are often 
called the Subclavian Veins ; but they do not appear 
to be accurately named. For, 1st, they are not situ- 
ated under the clavicle, and, 2dly, they are the com- 
mon trunks of the subclavians and internal jugulars 
united. 

There is a difference in the places where some of 
the smaller veins originate on each side, The inter- 



Superior Intercostal Veins* 308 

nal mammary ami the inferior thyroid, on the right 
side, arise from the superior cava, or from the sub- 
clavian at its origin. On the left side they arise from 
the subclavian. 

The SUPERIOR INTERCOSTAL Veins 

Are somewhat different on the two sides. That on 
the 7'ight is often the smallest and the least exten- 
sive. It commonly originates from the posterior and 
inferior part of the subclavian opposite to the origin 
of the vertebral, and is generally distributed to the 
first and second intercostal spaces, bat rarely to the 
third. 

The Left Intercostal frequently originates near the 
left internal mammary, and sometimes in common 
with it. It descends behind the aorta, on the left of 
the spine, and commonly sends oif the six upper in- 
tercostal veins, of which the two or three superior 
pass upwards from a part of the vein which is oppo- 
site to the third dorsal vertebra. Its extent is very 
different in different subjects. In some instances it 
passes so low as to supply the seventh or eighth in- 
tercostal space. This vein also gives off the Left 
Bronchial Vein^ which sends branches to the oeso- 
phagus and bronchial glands. 

The VERTEBRAL Veins 

Arise from the subclavians, but sometimes they pro- 
ceed differently iu different subjects : the right pass- 
ing behind, and the left before, the subclavian artery 
of its respective side. Each of them, however, be- 
comes contiguous to its corresponding artery. When 
it has arrived at the place in the transverse processes, 
where the artery enters the vertebral canal, it sends 
off an external branch, which passes up, before and 
nearly in contact with, those processes, and gives 
ramifications to the contiguous muscles, and also to 



304 Vertebral Veins. 

the cavity of the spine. These last mentioned rami- 
fications enter by the lateral apertures between the 
transverse processes, and anastomose with the veins 
and sinuses of the cavity. The branch often finally 
termiisates in the lateral sinus of the dura mater, by 
passing through the foramen near the mastoid pro- 
cess of the temporal bone. The Mmn Trunk of the 
vertebral vein generally sends off another external 
branch to the muscles near the basis of the neck, and 
afterwards enters the canal with the vertebral arte- 
ry. While in this canal, it generally sends off two 
branches through each of the lateral apertures be- 
tween the vertebrae. One of these branches passes 
backwards to the muscles of the neck ; and the other 
proceeds into the great spinal cavity, and commu- 
nicates with the venous sinuses. 

When it has arrived at the atlas, the Vertebral 
vein sends branches to the contiguous muscles of the 
neck. It also frequently sends a branch through 
the posterior condyloid foramen of the occipital bone 
to the lateral sinus. 

It is evident, from these circumstances, that the 
vertebral vein carries a portion of blood from the si- 
nuses of the brain and of the spinal marrow, as well 
as from the muscles of the neck, into the subclavian 
veins. 

The veins of the head are frequently very differ- 
ent in different subjects. 

The INTERNAL JUGULAR, 

Already mentioned, is often almost exclusively ap- 
propriated to the cavity of the cranium : and all the 
exterior veins of the head are ramifications of one or 
more smaller vessels, which pass up superficially on 
the neck, and are denominated External Jugulars. 
In some instances almost all the exterior veins of the 
head are united to the internal jugular at the upper 



The Internal Jugular. 305 

part of the neck, and it of course conveys the blood 
of the exterior as well as of the interior parts of the 
head. Frequently these veins are divided between 
the internal and exernal jugulars, but they are di- 
vided very differently in different subjects. 

The Internal Jugular, however, almost always 
passes in the same direction from the inside of the 
origin of the sterno-mastoid muscle to the posterior 
foramen lacerum of the cranium. It is deeply seat- 
ed on the external side of the common carotid artery, 
and under the sterno-mastoid muscle. Between the 
upper margin of the thyroid cartilage and the angle 
of the lower jaw, it often sends off branches which 
are very different in different subjects, but common- 
ly pass to the anterior parts of the neck and face : 
above these it generally sends another to communi- 
cate with the external jugular. One of the branches 
which often go off from the internal jugular is that 
which corresponds with the superior thyroid or la- 
ryngeal artery. This vein, which has sometimes 
been called the Guttural, sends many ramifications 
to the thyroid gland. The Ranular veins, which 
are so conspicuous under the tongue, are also de- 
rived from it ; and it likewise sends branches to the 
larynx and pharynx. 

Before the internal jugular enters the foramen la- 
cerum, it suffers a partial dilatation, which is general- 
ly larger on one side than the other.* This dilatation 
occupies the fossa at the foramen lacerum. After 
passing through the aforesaid foramen, the internal 
jugular terminates in the lateral sinuses of the dura 



♦ When the veins of the neck are injected, it very often appears 
that a considerable portion of the intei'nal jugular is much larger 
on one side than the other, as if it Avere affected with varicose dis- 
tention. 

It also often appears that the general arrangement of the exteri- 
or vein is different on the two sides of th« head and neck. 

Vol. II. 39 



306 The External Jugular. 

mater.* These and the other sinuses within the 
cavity of the cranium arc important portions of the 
venous system, which are interposed between the 
smaller branches spread upon the pia mater and the 
great trunks of the neck. They are described in the 
account of the brain, (Vol. 1. p. 316.) Into these si- 
nuses the very numerous veins of the rtepia ma 
open, proceeding to the sinuses in a direction the 
reverse of that in which the blood flows in those 
channels. 

These veins are divided very minutely on the pia 
mater before they enter the substance of the brain. 

Into one of these sinuses, denominated the Ca- 
ve7^nous, the ophthalmic vein discharges its contents. 
This vein proceeds from the anterior part of the 
sinus into the orbit of the eye through the sphenoid 
fissure. t Its ramifications correspond generally with 
those of the ophthalmic artery;}: and some of them 
pass out of the orbit to anastomose with the branches 
of the facial vein. 

The superficial veins of the neck are variously 
arranged in difliireut persons. There is often one 
considerable vein, 

The EXTERJVAL JUGULAR, 

Which is sent off by the subclavian, very near its 
union with the internal jugular; but sometimes it 
goes off from that vein much nearer the shoulder. 
There are sometimes two external jugulars, an ante- 



* It is asserted that the internal coat, or lining membrane of the 
internal jugulars, iscoiuinued into the lateral sinuses, and extends 
throughoutall the sinuses of the dura mater ; so that the bleod, 
during its passage through the sinuses, does not come in contact 
with any membrane different from that of the veins. 

f See the account of this fissure in vol. i. p. 63. 

% The Vasa Vorticosa of the choroides are one of the excep- 
tions to this. See vol. i, p. 356. 



Genti'al JlccGunt of the Great Vein of the Arm, 307 

vior and a posterior, nearly of cf^ual size. More 
frequently one of them is much smaller than the 
Other. In a majority of cases, the principal external 
ju2;niar goes off near the junction of the internal ju- 
£;nlar and subclavian, as above stated, and proceeds 
upwards towards the angle of the lower jaw, passing; 
between th.e platynnia myoides and the sterno-uiastoid 
muscle. It ofien sends oil, at the basis of the neck, 
one or more branches to tlie contiguous muscles, and 
then proceeds upwards. Near the angle of the jaw, 
it often c(>nimnnicates with the internal jugular : it 
then continues upwards, covered with the parotid 
gland, near the temporal artery, and finally divides 
into superficial and deep-seated temporal branches. 
The External Jugular, near the angle of the jaw, 
often sends off the facial vein, which crosses the 
basis of the lower jaw, near the facial artery, and 
distriI)Utes branches to the side of the face and to the 
forehead. It also very (jften sends off, near this 
place, the internal maxillary vein, which generally 
ramifies in such a mansier that its branches corre- 
spond with those of the internal maxillary artery. 
Veins which correspond to some of the other branches 
of the external carotid artery, the lingual, occipital, 
&c. are often sent off near this place h}^ the external 
jugular. They take tlie names of the arteries to 
u'hich tiiey correspond, and commonly accompany 
tliem. 

The SUBCLAVMJV Vein, 

Alihough it originates ditlVrently on the two sides of 
the inck, is siiuated alike on each of them. After 
parlinji; with the internal jugular, it proceeds over 
tjje first rib, under the clavicle, and (h)es not pass 
between the scaleni muscles, as is tiie case with the 
arteries, but before the anterior muscle, it soon 
joins tlie great artery of tliC arm, and proceeds be- 



308 General Jlccount of the Great Vein of the Arm. 

fore or below it to the axilla. la this situation it 
gives off branches to the contiguous parts, which 
correspond with those given off by the artery. In 
this course it also often gives off a large branch, 
called the 

CEPHALIC, 

Which soon becomes superficial, and proceeds down- 
wards between the margins of the deltoid and pec- 
toral muscles : it continues superficial on the external 
side of the biceps muscle, sending off many subcuta- 
neous branches. Near the external condyle of the 
OS humeri, it generally sends off a branch towards 
the middle of the anterior part of the fore arm, which 
is called the Median Cephalic, and also some other 
superficial branches. It then continues over the ra- 
dius, and inclining to the back of the fore arm, until 
it arrives at the back of the hand, where it divides 
into branches, some of which go to the thumb. 

In the axilla, the great vein, there called 
The AXILLARY Vein, 
Generally divides into two or three branches. One, 
which is commonly the largest, and appears like the 
continuation of the main trunk, is called 

The BASILIC Vein. 
This vessel passes down, deeply seated, to the bend 
of the elbow. It becomes superficial near the inter- 
nal condyle, and divides into several branches. — 
One of these generally proceeds to join the median 
branch of the cephalic, and from the union of the 
two branches is formed the median vein, which pass- 
es down near the middle of the anterior part of the 
fore arm. This vein generally sends off a branch 
which proceeds internally, and anastomoses with 
the deep-seated veins of the fore-arm. 

There are frequently two other branches of the 
basilic vein. One, which is small, passes down on 



Situation of the Inferior Vena Cava. 309 

the ulnar side of the anterior part of the fore-arm, 
but does not extend to the wrist. The other passes 
down on the ulna, and gradually proceeds to the 
back of the hand, when it divides into several 
branches, one of which is generally appropriated to 
the little finger. 

The AXILLARY vein, after the Basilic leaves it, 
sometimes divides into two branches, and sometimes 
continues undivided. In either case it accompanies 
the humeral artery, and takes the name of humeral 
Vein or Veins. It sends off branches which corre- 
spond to those of the artery, and continues to the bend 
of the elbow : here it is so divided, that two of its 
ramifications accompany each of the three arteries of 
the fore-arm. These ramifications sometimes com- 
municate with each other by anastomosing branches 
near the elbow, and they communicate also with the 
superficial veins. 

The superficial veins of the arm are so different in dif- 
ferent subjects, that a general description will rarely 
apply accurately to an individual case. It may, how- 
ever, be observed, that a Cephalic vein will generally 
be found, which very frequently arises from the sub- 
clavian instead of the axillary, and commonly conti- 
nues to the hand on the radial side of the arm. The 
superficial veins, on the ulnar side of the fore-arm, 
very frequently are branches of a large vein which ac- 
companies the humeral artery to the elbow, viz. the 
basilic; but the median vein, formed by branches of 
the cephalic and basilic veins, is very often not to be 
found. 

SECTION II. 

Of the INFERIOR VENA CAVA, and the Veins 
which are connected with it. 

This great vessel exceeds the Superior Cava in 
diameter. It proceeds from the lower part of the 



310 Situation of the Inferior. Vena Cava, 

right auricle, and very soon perforates the dia- 
phragm, at a small distance in front of the spine, 
and rather to the right of the centre. As the peri- 
cardium adheres to the diaphragm at this place, the 
vessel appears to leave it abruptly. Immediately 
after leaving the diaphragm, it proceeds along a 
groove in the posterior edge of the liver, formed by 
the great lobe and the iobulus Spigelii,* After 
leaving the liver, it continues downwards, inclining 
backward and to the left, and is soon in contact with 
the aorta, which is on the left of it. It accompanies 
the aorta to its great bifurcation, and divides in the 
same maiiner. It sends off, during this course, 
branches to the Diaphragm, Liver, Right Renal 
Gland, the Kidneys, and the Testicles ; and also 
the Lumbar and Middle Sacral veins. 

The Inferior Phrenic Veins 

Are thus denominated to distinguish them from other 
veins, which are derived from the internal mammary, 
&c. They generally accompany the phrenic arteries, 
and are distributed in the same manner. 

The HEPATIC Vei'ns 

Pass off from tlie vena cava, nearly at right angles, 
into the substance of the liver, while it is in the 
groove of that viscus, and before it has proceeded 
more than eight or ten lines from the heart.- 

They arise from the anterior part of the vena 
cava, and are generally three in number. Some- 
times there are two only, but i\\^\\ one of them di- 
vides immediately after it enters the substance of the 
gland. 

The distribution of these vessels in the liver has 

* Sometimes it is completely surrounded L'' the liver 



The Vena Povtarum. — Splenic Vein. 311 

been detailed in the accoiiutof that or:2;an, and there- 
fore, need not be stated here : but the veins wliich 
unite to form the vena portarum, and tlie trunk of 
that great vein also, before it is connected with the 
liver, may he regarded as a portion of the regular 
venous system, and ought now to be considered. 

The VEXA FORTARUM 

Passes downwards from the £;reat sinus of the liver 
behind the pancreas, and inclining to the left. In this 
course it sends branches to the gall bladder, the 
stomach and pylorus, and the duodenum. At the 
upper and posterior edge ()f the pancreas, it sends 
off a very large branch to the spleen, which often 
passes, with slight meanders, along a groove in the 
pancreas. 

The SPLEA'-IC Vein. 

Often sends off the inferior mesenteric vein, 
which proceeds downwards between the aorta and 
the left portion of the colon. It also sends off some 
of the coronary veins and the left gastro epiploic 
vein to the stomach ; many small branches to the 
pancreas; and, finally, either from the main trunk 
or its branches before they enter the spleen, the venae 
breves, which pass to the great extremity of the sto 
mach. Before it enters the spleen, it forms several 
ramifications, which accompany the branches of the 
splenic artery. 

After sending of the splenic, the Vena Fortarum 
takes the name of 

The SUPERIOR MESENTERIC Vein ; 
Which is larger than the splenic, and passes from 



312 Superior Mesenteric Vein.-r~Emulgent Veins. 

behind the pancreas, before the transverse portion of 
the duodenum, into the mesentery ; where it accom- 
panies the superior mesenteric artery. 

It is evident that the above described portion of 
the vena portarum simply performs the functions of a 
great vein ; but vi^hen it takes on the arrangements 
for entering the liver, it no longer acts like a vein^ 
but an artery. 

The lower portion of the trunk of this vein and its 
ramifications is denominated Vena Portce Ventralis. 
The part which ramifies in the liver, Vena Portce 
Mejpatica. 

The. Capsular Veins 

Are small vessels, one on each side. That on the 
right passes from the vena cava to the right glandula 
renalis. That on the left arises from the left erauU 
gent vein. 

The EMULGENT, or RENAL, Veins 

Are very large vessels ; and, like the arteries, go off 
nearly at right angles, one to each kidney. 

The right emulgent vein is not so long as the left, 
and it is rather anterior to its corresponding artery. 
The left emulgent, in its course to the kidney, crosses 
the aorta, and is anterior to it. 

These veins pass to the sinus of each kidney, and 
ramify before they enter it. The ramifications fol- 
lows those of the arteries. 

The Spermatic Veins 

Arise one on each side : the right from the vena cava, 
and the left from the emulgent vein. They proceed 
downwards behind the peritoneum, and on the psoas 
muscle generally divide into many branches, which 
communicate with each other as they progress down- 
wards, and form a plexus denominated Corpus 
Pamj)iniforme, These branches proceed in the 



• Internal Iliac and its Ramifications. 313 

spermatic cord to the back of the testis. The princi- 
pal part enters the body of that gland ; but some of 
the branches go the epididymis. In females the 
spermatic vein, like the artery, passes to the ovary, 
the uterus and its appendages, &c. 

The Lumbar Veins 

Correspond to the arteries of the same name. They 
arise from the posterior and lateral parts of the in- 
ferior cava, and those on the left side pass under the 
aorta. 

The Middle Sacral Vein 

Resembles the artery of the same name in its origin 
and distribution. 

The. IJVFEBIOB VEjYA CAVA accompanies 
the aorta to the space between tlie fourth and iifth 
lumbar vertebrae, and there it also divides into the 
two 

PRIMITIVE ILIAC VEINS. 

The left vein crosses behind the artery of the right 
side, and rather behind the left primitive iliac artery, 
which it accompanies until they are opposite to the 
junction of the sacrum and ilium, when it divides 
again, like the artery, into the internal and external 
iliac veins. 

The IJVTERJVAL ILIAC or HYPOGASTRIC 

Vein 

Descends into the pelvis behind the artery, which it 
accompanies. Its ramifications correspond in gene- 
ral with those of the artery, and, therefore, need not 
be particularly described. 

The VENiE VESICALES 

Have such peculiarities that their ramifications re- 
VoL. II. 40 



314 Ramijicatiom of the External Iliac, • 

quire particular attention. They arise from the hy- 
pogastric, very near the origin of the obturator, and 
are large as well as numerous. 

They are somewhat different in the two sexes. In 
men they form a remarkable plexus on the lateral 
and inferior portions of the bladder, and on the ve- 
siculaB seminales. This plexus extends more or less 
to the prostate : from it a number of veins proceed to 
the symphisis of the os pubis, which communicate in 
their course with the pudic vein. From thence 
arises the great vein of the penis, which proceeds in 
the groove between the corpora cavernosa, and ter- 
minates in the glans penis. This vein often divides, 
near the root of the penis, into two : one of which is 
in the groove, and the other more suj»erfi(ial.* 

In females, the venae vesicales form a considerable 
plexus on each side of the bladder and vagina. 
Many veins pass from these to the upper po! tions 
of the bladder and the contiguous parts, and form 
plexuses. The clitoris has a dorsal vein like the 
penis, and it originates in a manner analogous to the 
dorsal vein of the male. 

The EXTERJV^L ILIAC Vein. 

The great trunk of the veins of the lower extremity 
proceeds on the inside of the artery, under the crural 
arch or Pou part's ligament. Before it passes from 
under the arch, it sends off two branches which an- 
swer to the circumflex artery of the ilium and to the 
epigastric artery. 

The Circumflex Vein 

Arises from the external side of the iliac vein, and 
passes towards the anterior end of the spine of the 

* The pudic veins accompany the arteries of that name. They 
communicate with the plexus, as above mentioned, and continue 
injto the penis. 



Feins of the Leg. 315 

ilium. It divides into branches which accompany 
those of the artery of the same name. 

The Epigastric Vein 

Arises from the external iliac, and accompanies the 
epigastric artery.— After passing a small distance 
inward and downward, it turns up on the inside of 
the abdominal muscles. Jn the first part of its 
course it sends off some small branches to the sper- 
matic cord. 

After passing beyond Poupart's ligament, the 
name of the great vessel is changed from external 
iliac to 

FEMORAL VEIJV, 

It proceeds downwards at first on the inside of the 
femoral artery, but gradually changes its relative 
situation, so that in the thigh and in the ham it is 
behind or on the outside of that vessel. 

At a short distance below Pou part's ligament, af- 
ter giving off some small branches to the external 
organs of generation, and to the glands of the groin, 
it sends off on the internal side of the thigh a very 
large vein which is called the 

SAPHENA MAJOR. 

This vein immediately becomes superficial, and 
passes down on the internal side of the thigli, some- 
what anteriorly ; giving off some small branches to 
the contiguous parts, soon after it originates ; and 
many superficial veins afterwards. It continues along 
the inside of the knee and leg to the internal ankle, 
the anterior part of which it passes over. It then 
proceeds along the internal part of the upper surface 
of the foot to tlie middle, when it curves towards the 
external edge, and joins the lesser saphena. On tlie 



I 



316 Instances of peculiar arrangement of the Veins, 

leg and foot it also sends off many branches, which 
anastomose with each other, and with those of the 
aforesaid vein. 

The /emora/ vein, after parting with the saphena, 
soon sends off the vena profunda, and the circum- 
flexsB also, when they do not arise from the profun- 
da. These veins are generally larger than the arte- 
ries to which they correspond, and their branches; 
are more numerous ; but they observe the same 
course. 

The great vein accompanies the artery down the 
thigh and through the perforation in the biceps ; 
but it changes its relative position, so that it is 
placed behind or on the exterior side of the artery 
at the lower part of the thigh. It is very often be- 
hind it in the ham, where, like the artery, it takes 
the name of popliteal. In the ham it sends off 
another superficial vein, which seems very analo- 
gous to the basilar vein of the arm. This is called 

The Lesser or External Saphena. 

It proceeds from the ham over the external head of 
the gastrocnemius, and down the outside of the leg, 
sending off many branches in its course. It passes 
behind the external ankle and near the exterior edge 
of the upper surface of the foot, about the middle of 
which it inclines towards the great saphena, and 
forms with it the anastomosis already mentioned. 

The popliteal vein, after passing across the arti- 
culation, ramifies like the artery, but sends two 
veins, which accompany each of the three arteries of 
the leg. 



In a few instances some of the larger veins have 
been found to be arransi;ed in a manner very differ- 
ent from that which is commonly observed. 



Pulmonary Vessels, 317 

One case of this kind lias already been mentioned 
in the account of the liver,* where the Fena Porta- 
ru?n terminated in the Vejia Cava, below the liver, 
without entering into it. 

Another very remarkable instance of peculiar ar- 
rangement is to be seen in a preparation now in the 
University of Pennsylvania, in which the Inferior 
Cava, instead of opening into the lower part of the 
right auricle, passes behind it, in the tract of the 
Vena Azygos, and opens into the Superior Cava, in 
the place where the Vena Azygos usually commu- 
nicates with that vessel, receiving the Intercostal 
Veins in its course. 

In this preparation, the Hepatic Veins communi- 
cate directly with the right auricle, at its lower part ; 
the middle and left hepatic veins forming one trunk 
before they enter, and the right vein passing in 
singly.f 

Of the PULMONARY Arteries and Veins. 

Those portions of the Pulmonary artery and veins 
which are distinct from the lungs may be described 
very briefly. 

It has been already observed, f that the pulmona- 
ry artery arises from the left and most anterior part 
of the basis of the right ventricle, and proceeds 
thence obliquely backwards, inclining gradually to 
the left side for about eighteen or twenty lines, when 



* See note to p. 132, of this volume. 

t The foregoing preparation was made by the present editor in 1814, since which two 
"'I'll" ^""""alous cases have occurred to him. 

1819, Case Ist. The ascending cava passed into the thorax on the left side of the spine, 
and getting as far as its upper part, was joined there by the trunk of the internal jugular 
and subclavian oftJie left side. It there passed across the vessels of the arch ol the aorta 
and joined with the descending cava. The vessels of the liver entered the heart at the 
"'y*' P'^«e, in the lower part of the right auricle. 

*• 1 ? r^ '"^ ''"''^ trunk formed by the junction of the internal jugular and subclavian 
ofthe left side instead of taking its usual course, passed down vertically, before the left 
branch of the pulmonary artery and before the left auricle, then making a jlightcurvc 
between this auricle and the diaphragm joined with the ascending cava.— Ed. 

* See page 59 of this volume. 



318 Pulmonary Vessels, 

it divides into two branches, which pass to the two 
lungs. This course places it under the curve of the 
aorta: for that great vessel passes over the right 
branch of the pulmonary artery, and the right side 
of the main trunk of it, in such a manner that it 
proceeds downwards between the two branches and 
behind the angle formed by their bifurcation. From 
this place of bifurcation a short ligament proceeds 
to the lower part of the curve of the aorta, which is 
almost in contact with it. This ligament was origi- 
nally the canal that formed the communication be- 
tween the pulmonary artery and the aorta of the 
foetus. Each of the great branches of the pulmo- 
nary artery takes a direction backwards, and to its 
respective side. It soon joins the corresponding 
branch of the trachea and the two pulmonary veins, 
being anterior to the branch of the trachea, and 
above the pulmonary veins. It is also invested, in 
common with them, by that portion of the pleura 
which forms the mediastinum, and thus enters into 
the composition of the root of the lungs. 

Th^ Pulmonary veins are four in number — two 
on each side. In conformity to the mode of descrip- 
tion which we have adopted, it may be said that they 
arise from the sides of the Left Auricle, and proceed 
nearly in a transverse direction, two of them to each 
lung ; where they accompany the branches of the 
artery and of the trachea, being invested by the me- 
diastinum in common with these branches. It has 
been observed, that they differ from veins in gene- 
ral, by preserving a diameter nearly similar to that 
of the arteries which they accompany. 



SYSTEM OF ANATOMY. 

PART X. 



OF THE NERVES. 



The nerves are those whitish cords which pass 
from the brain and spinal marrow to the various parts 
of the body. 

A general account of their origin is contained in 
the description of the basis of the brain and of the 
spinal marrow,* which may be considered as intro- 
ductory to the present subject. 

The nerves, in general, appear to be bundles or 
fasciculi of small cords, each of which is composed 
of a series of fibres that are still smaller. These 
fibres consists of medullary matter, which is derived 
from the brain and spinal marrow, and is inclosed 
in a membranous sheath that appears to arise from 
the pia mater. The smaller the fibre, the more de- 
licate is the membrane which invests it. 

As the nerves proceed from the brain and spinal 
marrow, through the foramina of the cranium and the 
spine, they are inclosed in a sheath formed by the 
dura muter: but when they arrive at the exterior 
extremities of the foramina in those bones, this coat, 
derived from tlie dura mater, appears to separate 
into two laminae. Tijc exterior lamina combines 
with the periosteum, and the interior continues to in- 

* See volume I. page 333, 



320 General Structure of the J^erves. 

vest the nerve, but seems to change immediately into 
cellular substance ; so that the exterior coat of the 
nerves may be regarded as composed of cellular 
membrane, which is continued from the sheath de- 
rived from the dura mater. 

It has been supposed that the membrane which 
forms the sheaths for the medullary fibrils, of which 
the nerves are composed, is of a peculiar nature ; but 
it appears to be derived from the pia mater, invest- 
ing the brain and the spinal marrow. It is very 
vascular.* 

The ramification of a nerve is simply the separa- 
tion of some fibres from the general fasciculus. The 
branch commonly forms an acute angle with the main 
trunk. 

The course of these branches, from their origin to 
their termination, is generally as straight as possible. 

When the nervous cords are examined in an ani- 
mal recently dead, there is an appearance of white 
lines arranged in a transverse or spiral direction. 
The cause of this appearance is not well understood. 

In various parts of the body net works are formed 
bythe combination of different nerves,or the branches 
of nerves. In those instances the branches of one 
nerve, unite with those of another, and form new 
branches. These new branches again divide, and 
their ramifications unite with other new ramifications 
to form other new trunks. These new trunks divide 
again, and form new combinations in the same way. 

The trunks last formed proceed to the different 

* Several authors have written professedly on the structure of 
the nerves, viz. Monro, in his " Observations on the Structure and 
Functions of the Nervous System." — Bichat, " Anatomic Gene- 
rale. — Fontana, " Treatise on the Poison of the Viper." — Reil, 
*' Exercitationes AnatomicsD." — Scarpa, " Annotationes Academi- 
cse." — Prochaska, " De Structura Nervorum." 

I regret that it has not been in my power to procure Reil, Pro- 
chaska, or Scarpa. 



Plexuses. — Ganglions. 321 

parts of the body, as other nerves do which arise 
immediately from the brain. 

These combinations are denominated Plexuses. 
There are several of them in the cavities of the ab- 
domen and thorax, formed by the ramifications of 
the par vagum and the sympathetic nerves. The 
four lower cervical and the lii'st dorsal nerve form a 
very remarkable plexus of this kind, which extends 
from the side of the neck to the axilla, and forms the 
nerves of the arm. The lumbar nerves form a simi- 
lar plexusj although not so complex, which the cru- 
ral nerve arises. The anterior nerves of the sacrum 
also unite for the formation of the great sciatic nerve. 

It appears to be clearly ascertained, that the great 
object of this peculiar arrangement is the combina- 
tion of nervous fibres from many diiferent sources, in 
each of the nerves, which are distributed to any organ. 
Thus, the smaller nerves of the arm that are distri- 
buted to the diiferent parts, are not to be regarded 
simply as branches of any one of the five nerves 
which are approi)riated to the upper extremity, but 
as composed of fibres which are derived from each 
of them. 

Many of tlie nerves are enlarged in particular 
places, so as to form small circumscribed, tttmours; 
which are denominated Ganglions. 

Tiiese Ganglio?is are generally of a reddish co- 
lour. By very dextrous management, they can be 
shown to consist of a texture of fibres. The larger 
cords, which compose the nerve, seem suddenly to 
be resolved into the small fibres, of which they con- 
sist. These small fibres, after proceeding se[)a- 
rately a greater or lesser distance, according to the 
size of the ganglion, and changing their relative situa- 
tion, are again combined in cords which recompose 
the nerve. 

These fibres appear to be surrounded by a fine 

VoF,. IT. 41 



S22 Structure of Ganglions. 

cellular substance, which is vascular, moist and soft. 
It is asserted that, in fat subjects, an oily substance, 
resembling fat : and in hydropic subjects, a serous 
fluid has been found in this texture. 

Cranglions are often connected with but one nerve, 
which seems to enter at one extremity and go out at 
the other. But they frequently receive additional 
branches from other nerves, and send off additional 
branches to parts difterent from those to which their 
principal nerves are directed. When connected with 
but one nerve, they have been called simple gan- 
glions: when they receive and give off" additional 
branches, they are denominated compound gan- 
glions. — It does not appear that there is any impor- 
tant difference in their structure in these cases. 

The simple ganglions occur in the nerves of the 
spinal marrow — the posterior fasciculus of the nerves 
having always formed a ganglion before it is joined 
by the anterior fasciculus. The symphatic nerve, 
throughout its whole extent, forms compound gan- 
glions. 

The use of this particular structure does not ap- 
pear to be perfectly known. It seems, iiowever, cer- 
tain, that the different fibres — (of which the nerves 
forming ganglions are composed) — are blended to- 
gether and arranged in a manner different from that 
in which they were arranged before the nerve entered 
the ganglion. 

It ought to be observed, that the combination of 
nervous ilbrillsB, so as to bring together those fibrils 
which originally belonged to different cords, seems 
to have been kept in view throughout the whole ar- 
rangement of the nervous system. It is not only in 
the plexus and the ganglion that this appears, but 
also in some of the larger nerves ; for in them, the 
fibres which form the cords that compose the nerve, 
instead of running parallel to each other, along the 



Reproduction of JVerves, 3S3 

whole extent of the nerve, form a species of plexus 
in their course; separating from the fibres with which 
they were originally combined, and uniting with the 
fibres of other cords ; as in other cases of plexus.* 

There have been doubts respecting the possibility 
of a reproduction of the substance of the nerves when 
it has been destroyed ; but it appears to have been 
clearly proved by the experiments of Mr. Haighton, 
that a reproduction does really take place. | 

Nine pair of nerves proceed from the brain through 
the foramina of the cranium. They are called JVerves 
of the Bi'ain, or Cerebral JVerves. One pair passes oft" 
between the cranium and the spine, which is called 
Sub -Occipital. Twenty-nine or thirty pair pass 
through the foramina of the spine : they are denomi- 
nated Cervical^ Dorsal^ Lumbar and Sacral, from 
the bones with which they are respectively connect- 
ed. There are seven pair of Cervical nerves, twelve 
Dorsal, five Lumbar, and five or six Sacral — amount- 
ing, with the nerves of the brain, to thirty-nine or 
forty pair. 

A'ERVES OF THE BRAIJV. 

The nerves which go off from the brain and me- 
dulla oblongata are named numerically, according 
to the order in which they occur ; beginning with the 
anterior. Tliey also have other names, which gene- 
rally are expressive of the functions of the diiTerent 
parts to which tliey are distributed. 

Those which go to the nose are anterior to all the 
others, and are therefore denominated 

THli FIRST PAIR, OR THK OLFACTOUV NI^RVES. 

They arise by three delicate white fibres from the 

• See Monro's Oljservations 07i the Structure and Functions of 
the Nervous System. Phite xviii. 

t See London Philosophical Transactions^ for 1795, Part I. 



324 Olfactory Mrves. 

uticter and posterior part of the anterior lobes of the 
brain being (lerived from tlie Corpora Sti^iata. They 
])roceed forward to the depression on the cribriform 
plate of the ethmoid bone, on each side of the crista 
galli. The upper surface occupies a small sulcus 
formed by the convolutions of the lower surface of 
tlie brain, and, therefore, has a longitudinal ridge on 
it. The lower surface is flat. Their texture is like 
that of the medullary part of the brain. 

On each side of the crista galli each of them forms 
a pulpy enlari^ement of a brownish colour, which is 
called the bidb^ and has been considered as a gan- 
glion. 

From this bulb many fine and delicate cords go off, 
which proceed through the dura mater and the fora- 
mina of the cribriform plate to the Schneiderian . 
membrane. — These ramifications of the olfactory 
nerve seem to receive a coat from the dura mater, 
as they are much more firm after they have passed 
through it. They appear to be arranged in two rows 
as they proceed from the ethmoid bone — one running 
near to the septum, and the other to the opposite sur- 
face of the ethmoid bone.* 

THE SECOND PAIR, OR THE OPTIC NERVES, 

Originate from the T/ialami J^ervorum Opticorum, 
and appear on the external and lower surface of the 
brain, on each side of the sella turcica. 

Each of them seems like a cord of medullary 
matter, inclosed in a coat derived from the pia mater, 
and has not the fasciculated appearance of the other 
nerves. The medullary matter, however,, appears 
to be divided by processes that pass through it^ 
which are derived from the coat of the nerve. 

* See Vol. II. Page 6. 



Second and Third Pair of JVerves, 825 

They proceed obliquely forward and inward, on 
each side of the sella turcica, in contact with the 
brownish cineritious substance, in which the infun- 
dibuUun and the corpora albicantia of Willis are 
situated.* Anterior to this substance they come in 
contact with each other, and again separate, in such 
a way, that it is an undecided question whether they 
decussate each other, or whether each forms an an- 
gle, and is in contact with the other at the angle. 

From this place of contact, each nerve proceeds 
to its respective foramen opticum, where it receives 
a coat from the dura mater, which extends with it to 
tlie eye, as has been described in the account of that 
organ. 

THE THIRD PAIR OF NERVES 

Are sometimes called Motores Oculorum, in conse- 
quence of their distribution to several muscles of the 
€ye. They arise at the inside of the crura cerebri, 
and make their appearance on the basis of the braio, 
at the anterior part of the pons Varolii. 

They originate by numerous threads, which soon 
unite so as to form a cord which passes through the 
dura mater, on each side of tlie posterior clinold pro- 
cess, and continues through the cavernous sinus, and 
the foramen lacerum, to the orbit of the eye. 

Before this nerve enters the orbit it generally di- 
vides into two branches, whicli are situated one above 
the other. The Uppermost Branch is s[r)ent princi- 
pally upon the rectus superior muscle of the eye, but 
sends a twig to the levator palpebrse. The Inferior 
Branch is distributed to two of the recti muscles, 
viz. the internus and the inferior, and also to the 
inferior oblique. It likewise sends a twig to a small 
ganglion iu the orbit, called the Lenticular or Oph- 

♦ See Vol. I. p. 323. 



326 Fourth and Fifth Pair of N'erves. 

thalmic' Ganglion,* from which proceed the fine 
nervous fibres that perforate the sclerotica coat.f 

THE FOURTH PAIR OF NERVES 

Are called the Pathetic, in consequence of the ex- 
pression of the countenance produced by the action 
of the muscle on which they are spent. They arise 
from the side of the valve of the brain, below and 
behind the Tubercula QuadrigeminajJ and are so 
small that they appear like sewing thread. They 
proceed round the crura of the cerebrum, and appear 
on the surface between the pons Varolii and the 
middle lobes of the brain. They proceed along the 
edge of the tentorium which they perforate, and 
passing through the upper part of the cavernous si- 
nus, enter the orbit by the foramina lacera. They 
are exclusively appropriated to the Sujferior Oblique 
or Trochlearis muscle. 

THE FIFTH PAIR OF NERVES 

Are called Trigemina, because each nerve divides 
into three great branches. 

These nerves arise from tlie crura of the cerebel- 
lum where they unite to the pons Varolii, by distinct 
fibres, which are connected so as to form a cord or 
nerve, that is larger than any other nerve of the 
brain. In many subjects this cord seems partially 
divided into two portions, the anterior of which is 
much smaller than the posterior, and appears softer 
at its origin. 

It passes into a short canal formed by the dura 
mater, near the anterior extremity of the petrous por- 

* This ganglion, which is considered as the smallest in the body, 
lies Oil the outside of the optic nerve, near its entrance into the orbit, 
and is generally surrounded by soft adipose matter. 

•f See Vol I. page 356. 

X See Volume 1. Page 335. 



First Branch of the Fifth Pair, 327 

tion of the temporal bone, at a small distance below 
the edge of the tentorium. It is perfectly loose and 
free from adhesion to the surface of this canal ; but 
it soon passes out of it under the dura mater, and 
then adheres to that membrane. After leaving the 
canal it expands like a fan, but still consists of fine 
fibres which have some firmness. It is said tliat 
there are seventy or eighty of these fibres in the ex- 
pansion, but they appear to be more numerous. 
Round the circumference of the expansion is a sub- 
stance of a brownish colour, into which the fibres 
enter. This is the Semilunar Ganglion, or the 
Glangion of Gasser, and from it the three nerves 
go off. 

These nerves pass off from the convex side of the 
Ganglion, and are denominated the Ophthalmic, the 
Superior Maxillary, and the Inferior Maxillary. 

The Ophthalmic JVerve 

Passes into the orbit of the eye through the foramen 
lacerum : it there divides into several branches, 
which are called, from their distribution, the Frontal 
or Supra Orbit ar, the JVasal and the Lachrymal. 

The Frontal or Supra- Orbitar branch proceeds 
forward in the upper part of the orbit, exterior to 
the merabrance which lines it, and divides into two 
ramifications. One of these is small, and passes out 
of the orbit near the pulley of the superior oblique, 
to be spent upon the orbicularis muscle and the con- 
tiguous parts. 

The otiier ramification passes through the Supra- 
Orbitary Foramen, or through the notch, which is in 
the place of that foramen, and divides into a number 
of twigs, some of which pass transversely towards 
the side of the head, and communicate with twigs 
from the portio dura. Most of the others extend 
upwards on the head. Some are distributed to the 



328 Second Bi^anch of the Fifth Pair. 

anterior part of the occipito frontalis muscle, and the 
integuments of the forehead ; others are spent upon 
the upper portion of the scalp. Some of the ex- 
treme parts of these ramifications also communicate 
with the portio dura. 

The JVascd Branch proceeds obliquely forward 
towards the inner side of the orbit, and sends a twig 
in its course to the lenticular ganglion. It also sends 
oif some small twigs, to join the ciliary nerves which 
go from the ganglion. On the inside of the orbit a 
branch leaves it, which proceeds through the Fora- 
inen Orbitare Internum Jinterius to the cavity of 
the cranium, and passes a small distance upon the 
cribriform plate of the ethmoid bone, under the dura 
mater, to a fissure in the said plate near tlie crista 
galli, through which it proceeds into the cavity of 
the nose. Here it divides into twigs, some of which 
pass on the septum near its anterior edge, and ter- 
minate on the integuments at the end of the nose, 
while others pass down on tiie inferior turbinated 
bone. 

After parting with the ramification to tiie nose, the 
remainder of the nasal branch continues to the inter- 
nal canthus of the eye, and sends twigs to the la- 
chrymal sac, the caruncula lachrynialis, the eye-lids, 
and the exterior surface of the upper part of the 
nose. 

Tiie Laclirymal Branch proceeds obliquely for- 
ward and outwards, towards the lachrymal gland. 
In its course it sends off a twig which passes tlirough 
the sphenomaxillary fissure, and communicates witli 
a twig of the upper maxillary nerve, and one or 
more twigs that pass to foramina in the malar bone. 
The main branch passes to the lacln-ymal gland, and 
some twigs continue beyond it to the contiguous 
parts. 



Second Branch of the Fifth Pair, 329 

The Superior Maxillary J\''erve. 

The second branch of the fifth pair is examined 
with great difficulty on account of its peculiar situa- 
tion. It proceeds from the semilunar ganglion, and 
passes through the foramen rotundum of the sphe- 
noid bone into the upper part of the zygomatic fossa. 
In this situation it sends a twig to the orbit by the 
spheno maxillary fissure, and a branch, called the 
Infra Oi'bitar, which appears like the main nerve, 
as it preserves a similar direction, to the infra orbi- 
tar canal. At the same place it sends downwards 
two branches which unite together almost immediate- 
ly after their origin, and, as soon as they have uni- 
ted, enlarge into a ganglion.* This ganglion is call- 
ed the Spheno -Palatine. It is rather of a triangular 
figure, and lies very near the spheno- palatine fora- 
men. It gives off a posterior branch, which passes 
through the pterygoid foramen to the cavity of the 
cranium : some branches which proceed through the 
spheno palatine foramen to the n se, and are called 
the Spheno- Palatine or Lateral J\/asal JVerves: and 
an inferior branch, that proceeds through the poste- 
rior palatine canal, and is called the Palatiiie JVerve. 

The small branch, which was first mentioned, as 
going to the orbit by the spheno maxillary fissure, 
divides into two ramifications. One of them unites 
with a twig of the lachrymal branch above mention- 
ed, and passes out of the orbit, through a foramen in 
the malar bone, to the face; where it is distributed. 
The other passes also through a foramen of the ma- 
lar bone, into the temporal fossa, and, after uniting 
with twigs from tlie Inferior Maxillary JVerve, pro- 
ceeds backwards and perforates the aponeurosis of 

♦ Sometimes a single branch passes downwards instead of two ; 
but it forms a ganglion in the same place. 

Vol. II. 42 



330 Superior Maxillary J^erve, 

the temporal muscle, to terminate on the integuments 
of the temporal region. 

Before the Infra Orbitar branch enters the canal 
of that name, it sends off two twigs, called Posterior 
Dental Jferves, which pass downwards on the tube- 
rosity of the upper maxillary bune, and enter into 
small canals in that bone, that are situated behind 
the Antrum Maxillare. They subdivide into fine 
twigs that proceed forward to the alveoli of three 
or four of the last molar teeth ; and penetrate each 
of the roots by a cavity at its extremity. Twigs al- 
so proceed from these nerves to the posterior part of 
the gums and the buccinator muscle. 

After the posterior dental nerves have left it, the 
Infra Orbitar nerve proceeds forwards in the canal 
of that name ; and near the extremity of it, gives off 
the anterior dental nerve, which accompanies it for 
some distance, and then proceeds downwards in a 
canal in the bone anterior to the antrum maxillare. 
In its course this nerve divides into many fibres, 
which pass to the roots of the incisor, canine, and 
§mall molar teeth, each in its proper canal. These 
dental branches sometimes pass in the antrum maxil- 
lare between the lining membrane and the bones. 
The Infra Orbitar nerve passes out of the foramen 
upon the cheek, and divides into several branches of 
considerable size, which are distributed on the face 
from the side of the nose to the back of the cheek, 
and also upon the under eye-lid and the upper lip. 

The Pterygoid JVerve, or posterior branch, passes 
backwards, from the ganglion to a canal in the base 
of the pterygoid process of the Os Spheuoides, and 
proceeds through it. After leaving this canal, it 
passes through a substance almost as firm as carti- 
lage, which closes the anterior foramen lacerum, at 
the basis of the cranium ; and divides into ivfo 
branches^ The smallest of tb^^ called the Vidian 



Siiperior Maxttlarr/ J^ei'v^, Mi 

J^erve, proceeds with a small artery to the small 
ibranien, or Hiatus Fallopii, on the anterior side of 
the petrous portion of the temporal bone, and conti- 
nues, through a small canal, to join the Portio Dura 
of the seventli pair in the larger canal, called the 
Jlquediict of Fallopius, at tlie first turn in that ca- 
nal.* The other branch of the pterygoid nerve pro- 
ceeds to the Foramen Caroticum, and passes through 
it, with a twig of the sixth pair, to join the first cer- 
vical ganglion of the Intercostal JSlerve. 

ThaSphenO' Palatine, or Lateral JVasalA'^erves, con?- 
sist of several branches which pass from the spheno^ 
palatine ganglion through the spheno-palatine fora- 
men, into the nose. Some of them are distributed 
to tiiat part of the pituitary membrane, which is above 
the upper meatus, and others to the part which is im- 
mediately below it. Some of the branches which 
thus enter tlie nose are spread upon the septum ; one 
among them extends upon it, downwards and for- 
wards to the anterior part of the palatine process of 
the upper maxillary bone, where it enters into the 
foramen incisivum, and terminates in a papilla in 
the roof of the mouth. f 

The Palatine Branch proceeds, through the canal 
formed by the upper maxillary and palate bones, to 
the roof of the mouth and the soft palate. Soon af- 
ter its origin, it sends off a twig which proceeds 
down a small canal that is behind it. It also sends 
off, as it proceeds downwards, several twigs to that 

• The late Mr. John Hunter believed that this nerve parts from 
the portio dura at the lower end of the aqueduct, and is the chorda 
tymp;ini. 

t The curious distribution of this nerve appears to' have been 
known to the late John Hunter, and also to Cotunnius ; but it is mi- 
nutely described by Scarpa, and is delineated by Soemmering in his 
plate of the nose — Sec '* Observations on certain parts of the Ani- 
mal Economy," by J. Hunter, page 219, — and also Scar|)a " De Or-* 
pano Olfactus." In this last are some iuVeresting observa/tipns rcla* 
'iive to the ducts of Steno. 



332 Third Branch of the Fifth Pair. 

part of the membrane of the nose which covers the 
inferior turbinated bone. When it arrives at the 
roof of the mouth, it divides into several branches 
which run forwards, and are distributed to the mem- 
brane which lines the roof of the mouth. Some of 
its branches pass to the soft palate, the uvula, and 
the tonsils ; small filaments pass into the back part 
of the upper jaw. 

The Inferior Maxillary J^erve, or the Third Branch 
of the Fifth Pair, 

Passes through the foramen ovale into the zygoma- 
tic fossa, and divides into two branches^ one of which 
sends ramifications to many of the contiguous mtis- 
cies, as the Temporal, the Masseter, the Buccina- 
tor, the Pterygoid ; and also to the anterior part of 
the ear and the side of the head. The other branch 
passes between the pterygoid muscles, and divides 
into two ramifications, one of which proceeds to the 
tongue, and is called the Lingual or Gustatory, 
while the other passes into the canal of the lower 
jaw* 

The Lingual JVerve proceeds between the ptery- 
goid muscles, and in its course is joined by the 
choixla tympani. It continues forward between the 
maxillary gland and the lining membrane of the 
mouth ; and passes near the excretory duct of that 
gland, above the mylo-hyoideus and the sublingual 
gland, to the under side of the tongue, near the 
point: it then divides into a number of branches 
which enter into that body between the genio 
hyoideus and lingualis muscles.— This nerve has been 
supposed to be particularly concerned in the function 
of taste, because many of its branches continue to 
the upper surface of the tongue, especially near the 
point. In its course it has a communication with 
the ninth pair of nerves^ and it sends twigs io the 



The Sixth Pair ofMrves. 333 

membrane of the mouth and gums, and the contigu- 
ous parts. 

After parting with the lingual nerve, the inferior 
maxillary continues to the upper and posterior orifice 
of the canal in the lower jaw. Before it enters this 
canal it sends a branch to the sub-maxillary gland, 
and to the muscles under the jaw. It then enters 
the canal, attended by blood vessels, and proceeds 
along it to the anterior maxillary foramen, on the 
side of the chin, through which it passes out. In 
this course it sends twigs to the sockets of the teeth, 
and generally supplies all the large and one of the 
small grinders. Before it leaves the jaw it sends a 
branch forwards, which supplies the remaining teeth 
on the side to which it belongs. After passing out, 
through the anterior foramen, it is spent upon the 
muscles and integuments of the front of the cheek, 
the chin, and the under lip. 

THE SIXTH PAIR OF NERVES 

Are called Mo tores Externi. They arise from the 
commencement of the medulla oblongata, and pro- 
ceed forward under the pons Varolii. They pro- 
ceed through the dura mater on the inside of tlie 
fifth pair, and appear to pass through the cavernous 
sinuses, but are inclosed in sheaths of cellular mem- 
brane while they are in those sinuses. When in 
this situation they are near the carotid arteries, and 
each nerve sends off one or more very line twigs, 
which being joined by a twig from the pterygoid 
branch of the fifth pair, accompany the carotid artery 
through the carotid canal, and then unite themselves 
to the upper extremity of the upper cervical gaug- 
lion of the intercostal nerve. 

The sixth pair afterwards pass into the orbit of 
the eye, each through the foramen lacerum of its re- 



o34 Composition of the Seventh Pair,-^Portio Dura. 

spective side, and is spent upon the Rectus Externus 
or Abductor muscle of the eye. 

THE SEVENTH PAIR OF NKRVES 

Comprises two distinct cords which have very dif- 
ferent destinations ; and have, therefore, been con- 
sidered as different nerves, by several anatomists. 
One of these cords is appropriated to the interior of 
the ear, and is the proper Auditonj JVerve. The 
other is principally spent upon the face, and, there- 
fore, has been called the Facial. They have, how- 
ever, more frequently been denominated the Seventh 
Pair, and disiinguislied from each other, in conse- 
quence of a great difference in their texture, by the 
appellations o^ Portia Dura and Portio Mollis. 

These two cords pass off nearly in contact with 
each other, from the side of the upper part of the 
Medulla Oblongata, where it is in contact with the 
pons Varolii ; but the Portio Mollis can be traced to 
the fourth ventricle, while the Portio Dura is seen 
to rise from the union of the pons Varolii with the 
medulla oblongata and the crura Cerebelli. The 
Portia Dura, at its origin, is on the inside of the 
Portio Mollis. Between these cords are one or more 
small fibres, called Portio Media, which seem to 
originate very near them, and finally unite with the 
Portio Dura. 

Each of the seventh pair of nerves, thus com- 
posed, proceeds from its origin, to the Meatus Au- 
ditorius Internus of the temporal bone ; and the Por- 
tio Mollis divides into fasciculi, which proceed to 
the different parts of the organ of hearing, in the 
manner described in the account of the ear.* 

The Portia Dura enters an orifice at the upper 
and anterior part of the end or bottom of the Meatus 

* See volume I, page 2"6. 



Chorda Tympa7ii,-^Pes Anserinus. 335 

Auditorius Internus. This orifict^ is the commence- 
ment of a canal, which has been called the Aqueduct 
of Fallopius^ and proceeds from the Meatus Audito- 
riiis Internus to the external foramen, between the 
mastoid and styloid processes at the basis of the cra- 
nium. This canal first corves backwards and out- 
wards, near to the upper surface of the petrous bone, 
then forms an acute angle, and proceeds (back- 
wards and downwards) to the stylomastoid foramen, 
passing very near the cavity of the tympanum in its 
course. 

The Portio Dura, as it passes into the canal from 
the meatus internus, seems to receive an investment 
from the dura mater. It fills up the canal, but does not 
appear to be compressed. Near the angle it is joined 
by the twig of the vidian nerve, which proceeds from 
the pterygoid branch of the fifth pair, and enters the 
petrous bone by the small foramen innominatum on 
its anterior surface. In its course through the canal 
it sends off some very small twigs to the muscles 
and appurtenances of the small bones of the ear, and 
to the mastoid cells ; and, when it has arrived al- 
most at the end of the canal, it sends off, in a retro- 
grade direction, a small branch which proceeds into 
the cavity of the tympanum, (entering it by a fora- 
men near the base of the pyramid) and crosses the 
upper part of it, near the membrana tympani, be- 
tween the long processes of the Malleus and Incus. 
This twig is the Chorda Tympani: it proceeds from 
the cavity, by a fissure on the outside of the Eusta- 
chian tube, to join the lingual branch of the fifth 
pair, as has been already mentioned.* 

The Portia Dura, after passing out of the Fora- 

' The late John Hunter believed that tlie chorda tympani is 
merely a continimtion of the twig of the pterygoid branch which 
joins the portio dura above. — See Observations on certain parts of 
the Animal Economy, pagp 220. 



336 Composition of the Eighth Pair of JsTerves, 

men Stylo- Masioideum, is situated behind and with- 
in the parotid gland. Here it gives small twigs to 
the back of the ear and head, and to the digastric 
and stylo-byoideus muscles. It perforates the gland 
after sending filaments to it, and then divides into 
branches which are arranged in such a manner that 
they constitute what has been called the Pes An^ 
serinus. 

To describe the various branches in this expan- 
sion would be more laborious than useful. Some of 
them are spread upon the temple and the upper part 
of the side of the head, and unite with the supra- 
orbitar branches of the ophthalmic nerve. Some 
pass above and below the eye, and are distributed 
to the orbicularis muscle, and communicate with 
nervous twigs that pass through foramina in the ma- 
lar bone, &c. Some large branches pass transversely. 
They cross the masseter muscle, and divide into ra- 
mifications which are spent upon the cheek and the 
side of the nose and lips, and communicate with the 
small branches of the superior maxillary nerve. 

A large number of Ijranches pass downwards. 
Many of them incline forwards, and are spent on 
the soft parts about the under jaw; while others pro- 
ceed below the jaw to the superficial muscles and 
integuments of the upper part of the neck, communi- 
cating with the branches of the contiguous nerves.* 

THE EIGHTH PAIR OF NERVES 

Are very frequently denominated the Par Vagumy 
on account of their very extensive distribution. 

♦ A most minute and laborious description of the nerves of the 
face was published by the celebrated Meckel, in the seventh volume 
of Memoirs of the Royal Academy of Sciences of Berlin, for the year 
1751, accompanied with a plate, exhibiting the side of the head, of 
three times the natural size. This is republished in the Collectiou 
Academique: Partie Etrangere. — Tom. viiL 



Composition of the Eighth Pair of JVerves. 337 

They arise from those portions of the medulla ob- 
longata which are denominated the Corpora Olivaria. 
Each nerve consists of a cord, which is anterior, and 
called the Glosso- Pharyngeal ; and of a considerable 
number of small filaments, which arise separately, 
but unite and form another cord, the proper Par Va- 
gum. Associated with these is a third cord, called 
tlie Spinal, or Accessory JYerve of Willis, which 
originates in the great canal of the spine, and, pass- 
ing up into the cavity of the cranium, goes out of it 
with these nerves through the foramen lacerum. 

The two first mentioned nerves proceed from their 
origin to the posterior foramen lacerum, and pass 
through it with the Internal Jugular vein, — ^l)eing 
separated from the vein by a small process of bone. 
They are also separated from each other by a small 
process of the dura mater. In the foramen they are 
very close to each other : but soon after they have 
passed through it, they separate and proceed towards 
their diiferent destinations. 

The Glosso- Pharyngeal proceeds towards the 
tongue, between the siylo-pharyngeus and the stylo- 
glossus muscles, following the course of the last men- 
tioned muscle to the posterior part of the tongue. At 
the commencement of its course it receives a twig from 
the Portio Dura and one also from the Par Vagum, 
It soon gives off a branch which passes down on the 
inside of the common carotid to the lower part of the 
neck, where it joins some twigs of the intercostal to 
form the cardiac nerves. Afterwards it sends off 
several twigs to the muscles of the pharynx and its 
internal membrane, and also some twigs which unite 
with others from the upper cervical ganglion of the 
Syjnpathetic, and form a network tliat lies over the 
anterior branches of the external carotid. The 
Glosso- Pharyngeal finally enters the tongue, at the 
termination of the hyo-glossus muscle ; and after 

Vol. II. 43 



338 Glosso-Pharyngeal JSTerve. — Par Vagum. 

sending branches to the lingualis, and the various 
muscles inserted into the tongue, terminates in small 
ramifications that are spent upon the sides and mid- 
dle of the root of the tongue, and upon the large 
papillae. 

THE PAR VAGUM 

Are slightly enlarged after passing through the fora- 
men lacerum. As they descend^ they adhere to the 
superior ganglion of the intercostal, and also to the 
ninth pair. They proceed behind and on the out- 
side of the carotid, and are contained in the same 
sheath of cellular membrane Avhich incloses that ar- 
tery and the internal jugular vein. Each of these 
nerves, soon after it leaves the cranium, gives a twig 
to the glosso-pharyngeal ; that soon after it sends off 
a branch called the Pharyngeal, which unites to one 
from the accessory nerve, and to one or more from 
the glosso-pharyngeal, and proceeds to the middle 
constrictor of the pharynx, vv^hen it expands into 
ramifications that form a plexus from which proceed 
a number of small twigs that go to the larynx, and 
some that pass down on the common carotid artery. 

It then sends off, downward and forward, the Su- 
perior Laryngeal nerve, which continues in that di- 
rection behind the carotid artery, and divides into 
an external and internal branch. 

The Internal Branch, which is the largest, pro- 
ceeds between the os hyoides and the thyroid carti- 
lage; and divides into numerous ramifications which 
are distributed to the arytenoid muscles and to the 
membrane which lines the larynx and covers the epi- 
glottis. It is said, that fine twigs can be traced into 
the foramina, which are to be seen in the cartilage 
of the epiglottis ; — some ramifications can be traced 
to the pharynx; — others communicate with the 
branches of the recurrent nerve. 



Superior Laryngeal Branch of the Par Vagum. 339 

The External Branch sends twigs to the pha- 
rynx, to the lower and inner part of the larynx, and 
to the thyroid gland. 

In its course downwards, the great nerve some- 
times sends off a twig, which unites with one from 
the ninth pair that passes to the sterno-hyoidei and 
sterno-thyroidei muscles. 

It uniformly sends off one or more twigs, which 
pass into the thorax and combine with small 
branches from the sympathetic or intercostal nerve, 
to form the Cardiac Plexus, which sends nerves to 
the heart. 

After entering the thorax, the right trunk of the 
Par Vagum passes before the subclavian artery ; and 
the left trunk before the arch of the aorta ; and im- 
mediately after passing these arteries, each of the 
nerves divides into an anterior and posterior branch. 
The anterior is the continuation of the Par Vagurn ; 
the posterior is a nerve of the La?ynx ; which, from 
its retrograde course, is called the Recuri'ent JVerve, 

On the left side the Recurrent J^erve winds back- 
wards round the aorta, and on the right" side round 
the subclavian artery, and proceeds upwards, deeply 
seated, on the side of the trachea, to the Larynx. 
Soon after its origin it sends filaments to a ganglion 
of the sympathetic, to the cardiac plexus, and to a 
pulmonary plexus soon to be mentioned. In its 
course upwards it sends twigs to the trachea and the 
oesophagus. It proceeds behind the thyroid gland, 
and sends twigs to that organ. At the lower part of 
the larynx it sends off a branch which communicates 
with branches of the superior laryngeal nerve. It 
also divides into branches which are spread upon the 
p(»sterior crico-arytcnoid, and the arytenoid muscles ; 
and also upon the lateral crico arytenoid and the 
thyro-aryteuoid muscles, as well as upon the mem- 



340 Recurrent Branch of the Par Vagiim. 

brane wliich lines the back part of the larynx and the 
contiguous surface of the pharynx. 

There is a difference in the arrangement of the 
recurrents on the different sides, in consequence of 
one winding round the aorta, while the other winds 
round the subclavian artery. 

After sending off the recurrents, each trunk of the 
par vagum proceeds behind the ramifications of 
the trachea; but previously detaches some small 
branches, which are joined by twigs trom the inter- 
costal and from the recurrent, and form a plexus 
upon the anterior part of the vessels going to the 
lungs. This Anterior Plexus, after sending off some 
minute branches to the cardiac nerves and the peri- 
cardium, transmits its branches, with the bronchia 
and the blood vessels, into the substance of the lungs. 

Some of the branches which proceed from the par 
vagum, pass down on the posterior part of the tra- 
chea, and enter into the membiane which forms it, 
and the mucous glands which are upon it; and some 
pass to the oesophagus. 

When thie par vagum is behind the great vessels 
of the lungs, a number of branches go off transverse- 
ly, and are also joined by some fibres from the sym- 
pathetic. These form the Posterior Pulmonary 
Plexus; the ramifications from which proceed into 
the substance of the lungs, and are principally spent 
upon the ramifications of the bronchia. It has been 
said,* that the small twigs, into which they divide, 
very generally penetrate into the small ramifications 
of the bronchia, and are spent upon their internal 
membrane. 

Soon after sending off the nerves of the pulmona- 
ry plexus, the Par Vagum proceed downwards 

* See Buisson, in the continuation of tlie Descriptive Anatomy of 

Bichat. 



Different Functions of the Laryngeal, 8fC. 341 

upon the oesopbagus ; the left nerve being situated 
anteriorly, and the right posteriorly. Each of these 
nerves forms a plexus so as nearly to surround the 
oesophagus, as they descend on it ; but the network is 
thickest on the posterior side. They pass through 
the diaphragm with the oesophagus, and unite again 
so as to form considerable trunks. 

The Anterior, which is the smallest, proceeds along 
the lesser curvature of the stomach to the pylorus. 
Some of its fibres are spread upon the anterior side 
of the stomach and the lesser omentum. Others of 
them extend to the left hepatic, and also to the solar 
plexus. 

The Posterior trunk sends branches to surround 
the cardiac orifice of the stomach. Many branches 
are spread upon the under side of the great curvature 
of the stomach. Some of them nass in the course of 

I. 

the coronary artery to the coeliac, and unite to the 
hepatic and splenic plexuses ; and one trunk, which 
is thick^ although short, proceeds to the solar plexus. 

The Accessory JYevve of Willis, 

Which has been mentioned as associated with the 
eighth pair of nerves, within the cranium, has a very 
peculiar origin. 

It arises by small filaments, which come off from 
the spinal marrow, between the anterior and posteri- 
or fasciculi of the cervical nerves, and proceeds up- 
wards to the great occipital foramen, between these 
fasciculi. It commences sometimes at the sixth or 
seventh cervical vertebra, and sometimes about the 
fourth. It enters the cavity of the cranium through 
the foramen magnum, and proceeds upwards and 
outwards, so as to join the eighth pair of nerves at 
some distance from its origin, and in this course it 
receives filaments from the medulla oblongata. 

After approaching very near to the eighth pair of 



342 J^inih Pair ofJSi'erves. 

nerves, it accompanies it to the foramen lacerum, and 
passes out in its own separate sheatli. It then leaves 
the eighth pair and descends towards the shoulder, 
proceeding through the sterno mastoid muscle. Soon 
after it emerges from the cranium, it sends a ramifi- 
cation to the pharyngeal branch of the Pa?' Vagum 
and another to the par vagum itself. After pass- 
ing through the upper and back part of the sterno- 
mastoid muscle, it terminates in the trapezius. It 
adheres to the ninth pair of nerves as it passes by it, 
and sends a twig to the sub-occipital and some of 
the cervical nerves. It also gives ramifications to 
the sterno- mastoid muscle as it passes through it. 

It has already been stated that the Laryngeal and Re- 
current Nerves appear to answer different purposes in 
their distribution to the Larynx. — When both of the 
recurrent nerves are divided in a living animal, the 
voice seems to be lost. When the laryngeal nerves 
only are divided, the strength of the voice remains, 
but it is flatter. The recurrent nerves, therefore, 
seem essential to the formation of the voice. The la- 
ryngeal nerves are necessary to its modulation. 

The history of the investigation of this subject is 
contained in Mr. Haighton's paper in the third 
volume of Memoirs of the Medical Society of 
London. 

THE NINTH PAIR OF NERVES. 

Each of these nerves arises from the groove in the 
medulla oblongata, between the corpora pyrami- 
dalia and the corpora olivaria. Three or four fa- 
sciculi, of distinct filaments, unite to form it. Thus 
composed, it proceeds to the anterior condyloid 
foramen of the occipital bone, and passes through 
the dura mater. It seems firmly united, by the cel- 
lular membrane, to the eighth pair, and to the first 
ganglion of the sympathetic, soon after it passes 
from the occipital bone. It is either connected to 
the sub- occipital nerve by a small ramification, or it 



Mnth and Tenth Pair of JVerves, 343 

joins a branch wh\ch proceeds from the sub-occipital 
to the cervical, and bends round the transverse pro- 
cess of the atlas. It passes between the internal 
carotid artery and the internal jugular vein, and 
crosses the external carotid at the origin of the occi- 
pital artery. At this place it generally sends down- 
wards a large branch which is called the Descendens 
JVoni. Passing forwards, it is on the outside of the 
posterior portion of the digastric muscle, and inclines 
downwards ; but near the tendon of the muscle it 
turns upwards, and proceeds on the inside of the 
mylo-hyoideus, where it divides into ramifications^ 
which, at the anterior edge of the hyo-glossus mus- 
cle, begin to enter in the substance of the tongue, be- 
tween the genio-glossus and the lingualis muscles. 

Some of the branches of this nerve unite with 
those of the lingual branch of the fifth pair. Others 
are distributed to almost all the muscles connected 
with the tongue. 

The branch called descendens noni passes down 
in the course of the common carotid artery, and 
sends branches in its progress to the upper portions 
of the coraco-hyoidei and sterno-thyroidei muscles ; 
it unites with ramifications of various sizes from the 
first, second and third cervical nerves, which form a 
bow under the sterno- mastoid muscle, from which 
ramifications go to the lower portions of the sterno- 
hyoid ei and thyroidei muscles and of the coraco- 
hyoidei. 

OF THE CERVICAL JVEUVES. 

The tenth or last pair of the head, commonly call- 
ed the Sub-occipital, may be arranged with these 
nerves, because they arise, like them, from the medul- 
la spinalis, and are distributed to the muscles on the 
neck. 



344 Sub-Occipital, or Tenth pair of J^Te^'ves. 
The SUB-OCCIPITAL JVerves 

Arise on each side of the spinal marrow, nearly op- 
posite to the interval between the great foramen of 
the OS occipitis and the atlas. 

Each of these nerves consists of an anterior and 
posterior fasciculus, or bundle of fibres, which pass 
outwards immediately under the vertebral arteries, 
and form a ganglion, from which proceeds an ante- 
rior and a posterior branch. 

The anterior branch is united to the second cervi- 
cal nerve below, and to the ninth nerve, or the hypo- 
glossal, above. It also sends filaments to the upper 
ganglion of the great sympathetic nerve. 

The posterior branch is spent upon the Recti, the 
Obliqui, and some other muscles of the head. 

The prefer CervicalJVerves consist of Seven Pair; 
of which the first six go off between the vertebrse of 
the neck, and the seventh between the last of the 
neck and the first of the back. 

The FIRST CERVICAL JSTcrve 

Passes out between the atlas and the Vertebra Den- 
tata. It originates from two fasciculi, which are 
connected to each other at a ganglion, and then se- 
parate into an anterior and a posterior branch.* 

The antei'ior branch is connected by filaments with 
the accessory nerve, with the ninth pair of the head, 
and with the upper ganglion of the sympathetic. It 
is also connected with the second cervical nerve ; and 
sends some branches to the muscles on the anterior 
part of the spine. 

The posterior branch, after communicating with 
the posterior branches of the sub-occipital and the 

* This arrangement is common to the nerves of the spine. The 
ganglion is formed by the posterior fascicuhi-^- 



Cei'vical and Phrenic J^Terves. SIS 

second nerves of the neck, perforates the complexus 
muscle, and ascending upon the hack of the head, is 
distributed with the occipital artery. 

THE SECOND CERVICAL NERVE 

Sends off, from its Anterior Branch, a twig which 
descends to the lower cervical ganglion of the sym- 
pathetic, and a considerable ramification to the third 
cervical nerve It also sends off some twigs to the 
sterno-mastoid muscle, and others to join the acces- 
sory nerve. Some of its small ramifications pass 
down upon the external jugular vein, and others 
unite with the descending branch of the ninth pair 
of the head. A small branch is also concerned in 
the formation of the phrenic nerve. Two larger 
branches of this nerve wind round the posterior edge 
of the sterno-mastoid, and are spread under the in- 
teguments of the anterior, lateral and posterior parts 
of the neck and lower parts of the head ; they have 
a communication with the portio dura of the seventh 
pair.f — The posterior branch of this nerve is spent 
upon the extensor muscles of the head and neck. 

THE THIRD CERVICAL NERVE 

Sends down, from its Anterior Branch, the principal 
trunk of the phrenic nerve. It also sends twigs to 
the fourth cervical, to the lower cervical ganglion of 
the intercostal, and to the descending branch of the 
ninth of the head. Some of its branches unite with 
twigs of the accessory nerve, and others are spent 
upon the muscles and integuments of the shoulder 
and lower part of the neck. A small Posterior 
Branch is spent upon the muscles of the back of the 
neck. j; 

f These superficial branches have sometimes been described as 
coming from a plexus ; but they often arise directly from the Second 
Cervical nerve. 

Vol. II. 44 



346 CervicalJVerves, 

THE NERVES OF THE DIAPHRACiM 

Are generally denominated the Phrenic. The prin- 
cipal root of each of Ihem is commonly derived from 
the third cervical nerve, but freqiientiy the second 
and the fourth cervical nerves contribute to their for- 
mation ; and they are sometimes joined by a twig 
which is derived from the ninth pair. 

^ach nerve proceeds down the neck, between the 
rectus capitis major and the scalenus auticus, and 
continues along the fore part of the scalenus anticns; 
it descends into the tliorax within the anterior end 
of the first rib, between the subclavian vein and the 
artery. It sometimes receives a twig from the fifth 
cervical nerve, and a twig passes between it and the 
great sympathetic. After entering the thorax, they 
descend, attached to the mediastinum, before the root 
of the lungs. In consequence of the projection of the 
ifoint of the heart to the lei't, the course of the left is 
a little difl'erent from that of the right ; that of the 
ris;ht proceeding in a more perj)endicular direction^ 
When they arrive at tlie diaphragm, they divide into 
many ramifications, which have a radiated arrange- 
ment, and terminate on the fibres of t!iat muscle, both 
on the upper and lower surface. Some fibres from 
each nerve are continued downward, and communi- 
cate in the abdomen with fibres from the intercostal. 

THE I'OURTH, FIFTH, SIX 1 H, AND SEVENTH CERVICAL 

NERVES, 

May be comprised in one description. They pass 
off successively from the Medulla Spinalis, between 
the vertebrsB, like the other nerves. Their Posterior 
Branches are generally distributed to the back of tlie 
neck, and are very small. Their Anterior Branches 
are principally appropriated to the upper extremi- 
ties, and are large. They generally send each a 



Hemaining Cervical Js^erves, — Brachial Plexus. 847 

small twig to the lower cervical ganglion of the 
intercostal nerve, and a few .small branches to some 
of the contiauous muscles. They are arran2:ed and 
combined s as to form the network, now to be de- 
scnl)ed, which is called the Brachial or idocillary 
Plexus; and, in the formation of this plexus, they 
are joined by the first dorsal nerve. 

The BRACHIAL PLEXUS ' 

Extends from the lower part of the side of the neck, 
into the arm-pit. It commences in the f(dlowing 
manner. The fourth and fifth cervical nerves pro- 
ceed downwards, and after uniting to each other 
about an inch and a iialf below their egress from the 
spine, they separate again, almost immediately, into 
two branches. 

The sixth cervical nerve, after passing down- 
wards, divides also into two branches, one of which 
unites with th.e uppermost branch that proceeds from 
the union of the fourth and fifih, and the other with 
the lowermost, and they all proceed downwards. 

The seventh cervical is joined by the first dorsal^ 
which proceeds upwards, and unites with it at a 
short distance from the spine. The cord produced 
by their junction soon unites with one of the cords 
above described. As these d liferent cords proceed 
downwards, they divide, and their branches again 
unite. The axillary artery, which passes in the 
same direction, is surrounded by them. In this 
manner the axillary plexus is often formed. 

The muscles about the shoulder, both before and 
behind, are supplied by the axillary plexus. Thus, 
it sends branches to the Sub -scapular is, 7\res Major, 
and Latissimus Dorsi, behind; and to the Peciora- 
lis Major and Minor, and the Mamma., before. It 
also sends off a branch called the Scajiularis^ which 



348 JVerves of the Ann, 

commonly arises from the upper part of the plexus, 
and proceeds through the notch in the upper costa 
of the scapula, to the supra and infra spinatus, teres 
minor, &c, 

JVerves of the Arm. 

All tlie great nerves of the arm are derived from 
the axillarry plexus. There are six of them, which 
are denominated The Musculo Cutaneous ; the Me- 
dian ,•* The Cubital, or Ulnar ; The Internal Cuta- 
neous ; TTie Radial or Muscular Sph^al ; and the 
Circumflex or Articular. 

The Musculo Cutaneous, or Perforating JVerve, 
passes obliquely through the upper part of the coraco 
brachialis muscle. Before it enters the muscle, it 
sends a branch to it. After leaving the muscle, it 
passes down the arm between the biceps and the 
brachialis internus, to which it also gives branches. 
It proceeds to the outside of the biceps, and conti- 
nues under the median cephalic vein to the anterior 
and external part of the fore arm ; along which it 
passes, under the integuments. On the lower part 
of the fore arm it divides into many branches, which 
extend to the root of the thumb and the back of the 
hand, and terminate in the integuments. 

The Median JVerve, which is one of the largest of 
the arm, often proceeds from the axillary plexus next 
to the musculo cutaneous ; it passes down the arm, 
very near the humeral artery, within the edge of the 
biceps flexor muscle, and, during this course, gives 
off no branches of any importance. After passing 
the bend of the elbow, it proceeds, under the apo- 
neurosis of the biceps, between the brachialis inter- 
nus and the pronator teres, and continues down near 

* Sometimes called Radial. 



Median and Cubital or Ulnar JVerves. 349 

the middle of the fore arm, between the flexor subli- 
mis and the flexor profundus. At the elbow it sends 
branches to several muscles on the anterior side of 
the fore arm, and to the integuments. Among these 
branches is one, called the Inter ossealJS^erve^ which 
passes down on the anterior surface of the interos- 
seal ligament, with the artery of that name. This 
nerve sends branches, in its course, to the long flexor 
of the thumb and the deep flexor of the Angers. 
When it arrives at the pronator quadratus, it sends 
branches to that muscle, and, passing between it and 
the interosseous ligament, perforates the ligament, 
and soon terminates on the posterior side of the wrist 
and hand. 

As the Median JS^erve proceeds downwards, it 
becomes more superficial ; and continuing among the 
tendons of the flexors of the fingers, it gives oif a 
branch which is principally spent upon the integu- 
ments of the palm of the hand. This great nerve 
passes with the tendons under the annular ligament; 
and immediately after, while it is covered by the 
Jljjoneurosis Palmaris^ and by that portion of the 
artery which is called Arcus Sublimis, it divides into 
branches, which separate from each other at acute 
anji;le9, and subdivide so as to send a ramification to 
each side of the thumb, of the index, and of the mid- 
dle finger; and to the radial side of the ring finger. 
The Cubital or Ulnar JVerve is also of considera- 
ble size. It passes down on the inside of the triceps 
extensor muscle, to the great groove formed by the 
olecranon process and the internal condyle of the os 
humeri ; and in this course it often sends a branch to 
the triceps, and some smaller twigs to the upper part 
of the fore arm. From the groove it proceeds on the 
anterior part of the fore arm, between the flexor carpi 
ulnaris and the flexor sublimis, to the Avrist. At a 
small distance above the wrist it sends oft' a branch. 



350 JRadialy or Muscular Spiral JVerve. j^ 

Galled the DorsaUSf wliich passes between the flexor 
ulnaris aiul the ulna, to the back of the fore arm and 
wrist, wherej, after sending rainifications to the inte- 
guments and contiguous parts, it divides into branch- 
es which pass to the little finger and the finger next 
to it. Those branches send off, in their course, 
many twigs which pass to the skin and cellular sub- 
stance. 

The ulnar nerve then proceeds with the artery, 
over the annular ligament, on the radial side of the 
OS pisiforme, and divides into two branches; one of 
which is superficial, and tlie other deep-seated. 

The Superficial f\\.\\{{Q.s into two principal branch- 
es, an external and an internal. The external pass- 
es under the aponeurosis palmaris ; and, after send- 
ing a branch to combine with one from the median, 
and some twigs to the contiguous muscles, it subdi- 
vides into two branches, one of which goes to tlie 
ulnar side of the ring finger and the opposite side of 
the little finger. The other branch sends off some 
twigs to the muscles, and proceeds along the ulnar 
side of the little finger. 

The Beep-seated palmar branch of the ulnar nerve, 
passes between the muscles of the little finger, under 
the tendons of the flexors, and accompanies the deep- 
seated arterial arch in the palm of the hand, giving 
branches to the interossei, and other contiguous 
muscles. 

The Radial or Muscular Spiral nerve is one of 
the largest nerves of tlie arm. It passes from the 
axillary plexus downward, backward and outward, 
under the triceps muscle, to the external side of the 
OS humeri. In this course it gives off several branches 
to the different portions of the triceps. It also fre- 
quently gives off* a large branch, which passes down- 
wards on the outside of the olecranon, to the back 
of the fore arm, and continues to the back of the 



Radial, or Muscular Spiral JV'erve. 35 1 

hand; furnishing many brandies which terminate in 
the integuments. It then proceeds downwards be- 
tween the supinator radii longus and the bracliialis 
iutenius. Immediately after passing the articulation 
of the elbow, it divides into two branches, denomi- 
nated the Superficial and the Profound, The Su- 
perficial soon joins the radial artery, and proceeds 
downwards, sending brandies to the contiguous nius- 
des. In its course about the middle of the arm, it 
crosses the tendon of the supinator longus, and pro- 
ceeds between it and the tendon of the extensor carpi 
radialis longior; it soon after divides into twobranches, 
■\Alii<h are principally distributed to the thumb and 
fore finger, and also to the integuments. 

The Profound branch proceeds to the back of the 
fore arm under the radial extensor, and continues to 
the back of the wrist and hand. Into this course it 
divides into two branches, which are distributed to 
the contiguous muscles and tendons, and the inte- 
guments. 

The Internal Cutaneous nerve is the smallest of 
the nerves which proceed from the axillary plexus. 
Jt descends in the course of the basilic vein, and 
very near it. Above the elbow it divides into an 
Internal Branch, which proceeds over the Basilic 
Fein, and separates into branches that pass down 
on the side of the fore arm ; and an External Branch 
tliat passes under the Median Basilic Vein, and con- 
tinues down on the anterior part of the fore arm. 

The Articulai' or Circumfiex nerve proceeds back- 
wards from the plexus, between the teres major and 
minor, and passes nearly around the liody of the os 
humeri, at a small distance below its head. It is 
distributed to tlie cojitiguous muscles aiui to the arti- 
culation ; but its principal liranchcs terminate in the 
deltoid muscle. 



35^ The Dorsal JVerves. 

THE DORSAL A'EJRVES 

Proceed from the cavity of the spine between the 
dorsal vertebrae. They are sometimes called Inter- 
costals, because they pass between the ribs, like the 
blood vessels of that name. There are twelve pair 
of them, and they are named numerically, beginning 
from above. 

These nerves proceed from the medulla spinalis 
by two fasciculi of fibres — one from each of its late- 
teral portions — the posterior fasciculus is the largest. 
After passing through the lateral foramen and the 
dura mater, a ganglion is formed by the posterior 
fasciculus : the anterior fasciculus unites to this gang- 
lion at its external extremity; and one nerve is formed, 
"which almost immediately divides into an anterior 
and a posterior branch, of which the anterior is the 
largest. 

The posterior branch proceeds backwards, and is 
distributed to the muscles of the back. The anterior 
branch passes towards the angle of the rib, in con- 
tact with the pleura. Soon after its origin, this an- 
terior branch sends off two ramifications which unite 
to the intercostal nerve, at the ganglion ; it then pro- 
ceeds forwards with the blood vessels, between the 
internal and external intercostal muscles, in the 
groove near the lower margin of the ribs ; and ter- 
minates on the anterior part of the thorax. In its 
course it sends branches, not only to the intercostal 
muscles and pleura, but to the other muscles and the 
integuments of the thorax. 

Some of the dorsal nerves differ from the others, 
as to the ramifications which they send off. 

^he, first nerve, of this order, joins the lower cer- 
vical nerves in the axillary plexus ; but it sends off 
the ramifications to the sympathetic ; and also a 



^ 



General Account of the Lumbar JSterves. 353 

braucli, which passes under the first rib, like the 
other dorsal nerves. 

The second nerve, sends off a branch, which passes 
through the external intercostal muscle into the ax- 
illa, and combines there with a Ijranch of the cuta- 
neous nerve, being distributed to the internal and pos- 
terior part of tlie arm. 

The third dorsal nerve also sends off a branch, 
which is distributed to the axilla and the back part 
of the arm. 

These branches of the second and third dorsal 
nerves, are called intercosto- humeral nerves. 

The lower dorsal nerves supply the muscles and 
integuments of the abdomen. 

Of the L JJMBAR Kerves. 

There are five pair of these nerves. The first of 
them passes off between the first and second of the 
lumbar vertebrse . and the others succeed regularly ; 
so that the last pair is situated between the last lam- 
bar vertebra and the sacrum. 

The first lumbar nerves arise from the medulla 
spinalis, before it forms the cauda equina ; the other 
four pair are formed by the cauda equina, 

They commence by anterior and posterior fascicu- 
li, wliich are united at a ganglion. From this gan- 
glion, anterior and posterior branches go off, which 
are very different in size, tlie anterior being the lar- 
gest. 

The posterior branches are distributed to the raus'- 
cles of the back. The anterior send branches to the 
ganglions of the sympathetic nerve, and also commu- 
nicate with each other to form tlie Lumbar Vlexm, 
which is situated on the lateral parts of the bodies of 
the Lumbar Vertebrse, before their transverse pro- 
cesses, and supplies nerves to the muscles of the 
thigh. 

Vol. II. 45 



354 Lumbar jVerves. — Lmnbar Plexus, 

THE FIRST LUMBAR NERVE 

Is connected, by its anterior branch, to the last dor- 
sal and the second lumbar. From the same brand), 
ramifications go off to the Quadratus Lumborum, and 
obliquely across that muscle, to the lower part of the 
abdominal muscles near the spine of the ilium. 

THE SECOND LUMBAR NERVE 

Sends off a muscular branch downwards and out- 
wards : it also sends off the small branc?), called the 
External Spei-inaiic, which passes down in such a 
direction, that it perforates the transversalis and the 
obliquus internus muscles, near their lower margin, 
at a small distance from the superior anterior spine 
of the ilium, and then proceeds within the lower edge 
of the tendon of the external oblique to the abdomi- 
nal ring, through which it passes. In the male it is 
distributed to the spermatic cord and scrotum, and in 
the female, to the labia pudendi. In the female it 
also sends a branch to the uterus.* The Second 
Lumbar, after sending off these branches, passes 
downwards, and joins the TA?>f/ lumbar nerve. From 
this union of the second and third nerves, a branch 
called the Cutaneous Medius, which will be soon de- 
scribed, proceeds downwards. 

After sending off this branch, the united trunk of 
the second and third joins the Fourth; and from this 
union are sent off the Obturator JVerve, which passes 
through the aperture in the membrane that closes the 
foramen thyroideum ; the CruralJVerve, which passes 
under Poupart's ligament ; and a third branch that 
proceeds downwards, and joins the Fifth lumbar 
nerve. The Fifth lumbar nerve, with this accession 
from above, descends into the pelvis, and unites with 
the sacral nerves. 

• The external spermatic often comes off from the first lumbar 
nerve. 



Obturator J^^erve. — CruralJ\*erve. 355 

This arrangement of the lumbar nerves constitutes 
the Lumbar Plexus, which, as has been already sta- 
ted, furnishes three nerves to the lower extremity, 
viz. the Cutaneous Medius, the Obturator^ and the 
Crural JV'erve. 

The Cutaneous Medius which arises from the 
union of the second and third nerves, as has been 
already observed, proceeds downwards, and frequent- 
ly adheres to the crural nerve, for a short distance, 
near Poupart's ligament, but soon leaves it, and de- 
scends on the inside of the thigh, supplying the in- 
teguments as low^ as the knee. 

THE OBTURATOR NERVE 

Descends into the pelvis, and passes out of it at the 
upper part of the foramen thyroideum ; proceeding 
downwards in an internal direction, to be distributed 
on the inside of the thigh. 

This nerve is generally accompanied by the obtu- 
rator artery and vein ; the artery being above, and 
the vein below it. When it has arrived at the fora- 
men ovale or thyroideum, it sends off a branch to 
the internal and external obturator muscles, and, 
after passing these muscles, divides into two branches 
which are distributed to the muscles on the inside of 
the thighs, the adductors, the pectineus, the graci- 
lis, &c. 

THE CRURAL NERVE 

Is situated at first behind, and then on the outside of 
the psoas muscle. It passes under Pou part's liga- 
ment with the great femoral vessels, being on the out' 
side of the artery. 

It is distributed to the integuments, and also to 
the muscles, which are situated on the anterior and 
internal parts of the thigh. Some of its ramifications 
go off before it passes under Poupart's ligament. 



356 Crural JMerve.—rSaeral J\^erves. 

Several of them are spent upon the integuments, and 
are therefore denominated Cutaneous. — They are 
distinguished by the terms Cutaneous Anterior, Cu- 
taneous InternuSf &c. according to their situations. 

The deep-seated branches are the largest. They 
are principally spent upon the muscles on the ante- 
rior and the internal side of the thigh, viz. the four 
extensors, the adductors, the pectineus, the sartorius, 
and the gracilis. Among these nerves there is one, 
called the Saphenusj which has a different destina- 
tion. It accompanies the great artery of the thigh to 
the place where it perforates the Adductors : it there 
separates from the artery, and passes over the tendon 
of the Adductors, under the sartorius muscle ; thence 
it continues, with the great saphena vein, on the in- 
side of the leg, to the internal ankle; sending branches 
to the integuments in its course. It terminates in skin 
and cellular substance on the upper and internal sur- 
face of the foot. 

The SJiCRAL J^erves 

Are composed of those cords of the cauda equina, 
which remain after the formation of the lumbar 
nerves. They are frequently stated to consist of 
five or six pair, four of which pass through the fo- 
ramina of the sacrum, and the fifth between the sa- 
crum and the os coccygis.* The cords of which 
they are respectively composed arise by anterior and 
posterior fasciculi. When they have arrived oppo- 
site to the foramina of the sacrum, through which tiiey 
are to pass, a ganglion is formed, at which they 
tinite, and then divide into anterior and posterior 
branches.f The uppermost of the anterior branches 

* The sixth pair, when they exist, proceed in a groove in the os 
coccygis, 

t The ganglions of the fourth and fifth nerves are extremely 
small and not so near the foramina as thosq of the others. 



Sciatic Plexus. — Pudic J\''erve. 357 

are large, and pass through the auterior foramina of 
the sacrum. The posterior are small, and go through 
the posterior foramina. 

The Posterior Branches are generally spent upon 
the muscles which lie on the sacrum, and posterior 
parts of the pelvis, externally. 

The anterior branches of the three first nerves 
send ramifications to the sympathetic. They unite 
to each other, and are joined by the last lumbar 
nerve, and by a branch of the fourth sacral, in the 
formation of the great sciatic nerve. This union 
constitutes the Sciatic Plexus. 

The anterior branch of the fourth nerve transmits 
branches to the sympathetic : it also sometimes sends 
a branch to the united nerves above, or the sciatic 
plexus. It sends branches to the hypogastric plexus, 
and to the contiguous muscles. 

The fifth and sixth pairs, which are very small, 
terminate also in the contiguous muscles and in the 
integuments. 

From the Sciatic Plexus, or the nerves which 
compose it, several smaller branches go off. There 
are generally two which pass off backwards through 
the ischiatic notch, and are denominated Gluteal, as 
they are distributed to the glutei muscles. From the 
lowermost of these a branch descends on the thigh. 

The Pudic JVerve, whicli is appropriated to the 
organs of generation, also passes off from this plexus, 
and appears to consist of fibres which are derived 
from each of the nerves that compose it. It proceeds 
between the sacrosciatic ligaments, and divides into 
two* branches — an inferior and a superior. The 
inferior passes between the erector penis and the 
accelerator urinae muscles, and is distributed to those 
muscles, to the bulb of the uretlira and the interior 
of that canal, to the scrotum and dartos, 

The superior proceeds along the os pubis to the 



358 Course of the Great Sciatic J^ervc. 

symphisis, and passes between the bone ami the 
body of the penis to the dorsum. A considerable 
branch accompanies the artery on the dorsum, and 
terminates, by many ramifications, on the glans 
penis ; after sending branches in its course to the 
integuments generally, and to the prepuce. 

In females, the Inferior Pudic JVerve proceeds 
along the external labia pudendi to the raons veneris, 
sending off many ramifications in its course. 

The Superior Pudic Merve proceeds, as in males, 
along the branch of the pubis to the superior surface 
of the clitoris, and terminates principally upon the 
extremity of that organ. 

The sacral nerves unite in the sciatic plexus to 
form the great nerve of the lower extremity, which 
is next to be described. 

The GREAT SCIATIC JVerve 

Proceeds from the pelvis through the ischiatic notch, 
between the pyramidalis and the superior gemellus 
muscle : it then passes down to the back part of the 
thigh, between the tuberosity of the ischium and the 
great trochanter of the os femoris ; and continues 
downwards, inclining from within outwards, to the 
ham, where it is situated between the tendons of the 
semi-tendinosus and semi-membranosus on the inter- 
nal side, and the tendon of the biceps on the exter- 
nal, In this course it sends off branches to the 
muscles on the posterior part of the thigh. 

As the great nerve passes down the thigh, it sends 
off obliquely, downwards and outwards, a l^rge 
branch which is called the Fibular, that p&sses 
across the head of the fibula to the external and 
anterior part of the leg. The place where this 
branch separates from the main nerve is different in 
different subjects. It continues in contact with it 



Distribution of the Fibular J^erve. 359 

for some distance, connected only by cellular mem- 
brane. 

THE FIBULAR OR PERONEAL NERVE 

Proceeds downwards on the inside of the tendon of 
the biceps, and crosses obliquely to the outside of the 
external head of the gastrocnemius : it then passes 
inwards between the long peroneus muscle and the 
fibula ; and descending between the muscles on the 
front of the leg, divides into two branches, .one of 
which inclines to the exterior side of the leg, and 
the other preserves an internal situation. In its course 
from the great sciatic nerve to the fibula, it sends off 
some superficial ramifications. The two branches 
into which it divides, after passing over the fibula, 
continue downwards. The Internal, after supply- 
ing the muscles on the anterior part of the leg, 
passes under the annular ligament like the anterior 
tibial artery ; and on the upper part of the foot, di- 
vides into two ramifications, one of which proceeds 
forwards near the internal edge of the foot, and the 
other near the external ; they divide again, and are 
distributed to the parts on the upper surface of the 
foot, one of their ramuli descending with the conti- 
nuation of the anterior tibial artery to the sole of the 
foot. 

The External Branch of the fibular nerve, as it 
proceeds downwards, supplies ramifications to the 
contiguous muscles, and passing through the fascia 
on the outside of the leg, continues between it and 
the skin towards the foot. In this course it gene- 
rally divides iuto two branches which are spent upon 
the upper surface of the foot. 

The GREAT SC lATIC JVerve, after the fibular 
nerve leaves it, continues down the thigh, between 
the tendons of the flexors, behind the great blood 
vessels, and of course exterior to them. 



i 



360 Distinhution of the Tibial Nerve. 

In the ham, this great nerve takes the name of 
POPLITEAL^ and proceeds across the articulation 
of the Ivnee, between the heads of the gastroc nemii, 
to the posterior side of the tibia : here it passes 
through the upper portion of the soleus or gastroc 
nemius internus, and continues between it and the 
long flexor of the toes, near the Posterior Tibial 
Artery ; descending with that artery to the hollow of 
the OS calcis. In this situation it has the name of 

POSTERIOR TIBIAL NERVE. 

At the commencement of this course, a small dis- 
tance below the internal condyle of the os femoris, 
it sends off a branc h of considerable size called the 
Communicans Tibise, or Saphena Externa^ which 
passes down behind the gastroc nemii, and gradual- 
ly inclines externally, so that it is situated on the 
external edge of the tendo Achillis, soon after the 
commencement of that tendon, and proceeds behind 
the external ankle, near the outer side of the foot, to 
the smaller toes ; distributing branches to the conti- 
guous parts. In its course on the back of the leg, 
it sends off a branch which unites with one of the 
superficial ramifications of the fibular nerve, and de- 
scends to the outer part of the foot. 

The Tibial JVerve, in its course downwards, sends 
branches to the contiguous muscles ; and a few twigs 
which form a species of network on the artery. In 
the hollow of the os calcis it sends off a superficial 
branch to the integuments of the sole of the foot, 
which proceeds on the outside of the aponeurosis 
plantaris ; it there also divides into branches, which 
are denominated the Internal and External Plan- 
tar JVerves. 

The Internal Plantar JVerve proceeds forwards, 
along side of the tendon of the long flexor muscle of 
the great toe, giving off small branches in its course 



Commencement of the Sympathetic Aen'e. 36 i 

About the middle of the foot it divides into four 
branches, one of which proceeds to the inside of the 
great toe ; and a second to the angle formed by the 
great toe and the toe next to it, where it divides and 
sends a braneh to the opposite sides of those toes : 
the other two branches are distributed in a similar 
manner, to the succeeding toes. These digital 
branches are connected with each other by small ra- 
mifications. 

The External Plantar JS'^erve proceeds with the 
external plantar artery towards the external side of 
the foot, between the short flexor of the toes and the 
flexor accessorius. Near the external edge of the 
foot, about the posterior end of the metacarpal bones, 
it divides into three branches. One proceeds to the 
outside of the little toe ; another passes to the angle 
between the fourth toe and the little toe, and divides 
into branches which are distributed to the corre- 
sponding sides of these toes. The third branch pro- 
ceeds more deeply in the foot, from the external to- 
wards the internal edge of it, and is spent upon the 
deep-seated contiguous muscles, 

THE GREAT SYMPATHETIC OR INTERCOSTAL NERVE 

Commences in the cranium with those small ramifi- 
cations of the pterygoid branch of the upper maxil- 
lary nerve, and of the sixth pair, which accompany 
the carotid artery through the canal in the petrous 
portion of the temporal bone. These small nerves 
form a network which surrounds the artery in the 
canal, and gives rise to the incipient sympathetic, a 
small cord which passes down close to the nerves of 
the eighth and ninth pair of the neck. Opposite to 
the second cervical vertebra, this nerve is swelled or 
dilated, so as to form a body of a light red colour, 
which is more than an inch in length, and has the 
form of two cones united to eacli other at their bases. 
This is the Superior Cervical Ganglion of the Sym- 
Vol. 11. 46 



362 First Ganglion, and other Cervical 

pathetic J\re?'ve, and from it the nerve descends, be- 
hind the Par Vagum, on the front part of the neck. 

This ganglion receives twigs from the first, second^, 
third and fourth pairs of cervical nerves, and also 
from the eighth and ninth nerves of *the head. It 
sends otr several twigs, which pass behind the caro- 
tid artery, at its bifurcation, and are joined by twigs 
of the PortioDura and the Glossa- Pharyngeal ntxvQS. 
From these united twigs proceed very small ramifi- 
cations, which accompany several branches of the 
external carotid artery, and some of them pass down 
with the Common Carotid. 

This superior ganglion also furnishes small twigs 
which accompany the Glosso-PharyngealiothGtou^uc 
and pharynx. Sometimes a twig from it passes on 
the back part»of the thyroid gland to communicate 
with the recurrent nerve. From this ganglion go 
off some small branches, which, uniting with others 
from the superior laryngeal nerves, form the supe- 
rior or superficial cardiac nerve, which will be soon 
described. 

The trunk of the Sympathetic JYerve descends, on 
the front of the neck, from this ganglion, as has been 
already stated. In its course it receives very small 
twigs from the fourth and fifth cervical nerves, and 
sends some very small twigs which appear to go 
to the oesophagus, and some which unite to the la- 
ryngeal nerve and go to the thyroid gland. Some 
twigs, which are larger, proceed from it into the 
thorax, and go to the cardiac plexus hereafter to be 
described. 

Opposite to the interval betv^'een the fifth and 
sixth cervical vertebrae it forms another ganglion, of 
an irregular shape, much smaller than the first. This 
ganglion, in different subjects, differs in size as well 
as in several other respects. Sometimes it is en- 
tirely wanting, and sometimes it is doubled. It is 



Ganglions and Branches of the Sympathetic. 363 

denominated the Middle Cervical, or Thyroid Gang- 
lion. When the fourth, fiftli, and sixth cervical 
nerves do not send ramifications to the sympathetic, 
nerve, this ganglion receives twigs from them. 

The Middle Cervical, or Thyroid Ganglion, sends 
many ramifications downwards. Some of them enter 
the thorax and contribute to the formation of the 
Cardiac Plexus; others accompany the inferior 
thyroid artery, and, with twigs from the recurrent 
nerve, form a plexus which extends towards the 
thyroid gland. Some proceed downwards before, 
and others behind, the subclavian artery, to the next 
ganglion ; and among them is generally one which 
may be regarded as the trunk of the Sympathetic. 

This third Ganglion is denominated the Inferior 
Cervical, or the First Thoracic. It is almost con- 
stantly found in the same situation, viz. between the 
transverse process of the last cervical vertebra and 
the head of the first rib, aud is partly covered by the 
origin of the vertebral artery. It is generally larger 
than the middle ganglion. It receives branches from 
the sixth and seventh cervical, and the two first dor- 
sal nerves. Ramifications pass from it to the par 
vagum and recurrent nerve, and also to the cardiac 
and pulmonary plexus. 

From this ganglion the Sympathetic JSTerve pro- 
ceeds dow nwards on the side of the spine, as will be 
described hereafter. 

Tlie JVerves of the Heart, 

Being derived from branches which have already 
been mentioned, are now to be described. 

They arise principally from an arrangement of 
nerves denominated the Cardiac Plexus, or Plex- 
uses, which is situated about the curve of the aorta, 
and extends, on the posterior side of it, from the 
root of the arteria innominata to the bifurcation of 



364 Branches of the Syinpathetic. 

the pulmonary artery. This plexus is composed of 
nerves which are principally formed by the union 
of small ramifications that are derived from the three 
above mentioned ganglions of the Sympathetic JVerve, 
and the nerve itself ; and also from the Par Vagum 
and some of its branches. 

These nerves are denominated the Cardiac. — 
They descend on their respective sides of the neck, 
but are somewhat different on the different sides. — 
On the right side three nerves have been described 
as particularly entitled to this name, and on the left 
side but two. 

The first on the right side is denominated Supe- 
rior or Superficial Cardiac JYerve. It generally 
arises by several fine threads, which unite into one 
delicate cord that passes down by the side of the 
common carotid. When it has arrived on a line 
with the middle ganglion, it sends a twig to the thy- 
roid plexus, and another that communicates with a 
twig from the par vagum, which continues down- 
wards on the carotid artery. After passing beyond 
the ganglion, it divides into several branches, which 
unite themselves to branches of the recurrent nerve 
that are going to the middle ganglion. 

The second, which is denominated the Middle 
Cardiac, the Great Cardiac, or the Deep Cardiac^ 
is the largest of the three. It arises from the Mid- 
dle Cervical or Tliyroid Ganglion^ by five or six fine 
fibrils, which finally form one, that passes before 
an J across the subclavian; and at that place, as 
well as lower down, it receives twigs from the par 
vagum : below this, it is joined by a considerable 
twig from the recurrent, and terminates in the Car- 
diac Plexus, to which it contributes largely. 

The third cardiac nerve of the right side is called 
the Inferior, or the Small Cardiac JVerve. It origi° 
nates from the third; or lower cervical ganglion, by 



Branches of the Sympathetic, 365 

many fibrils which unite into a smaller number that 
form a plexus. It crosses behind the subclavian, 
and proceeds on the outside of the Arteria Innomi- 
nata to the curve of the aorta ; continuing between it 
and the pulmonary artery, to the anterior coronary 
plexus. In this course it receives several fibres from 
the recurrent and the pjir vagum. 

On the left side the first cardiac nerve arises from 
the upper ganglion. The second derives its origin 
from the two lower ganglions. 

The left superior or superficial cardiac nerve arises 
like the right, by many distinct fibres, and proceeds 
downwards in the same way. It descends between 
the carotid and the subclavian, and when it has ar- 
rived at the place where they originate from the aorta, 
it divides into a great number of small ramifications. 
Some pass before the aorta, either to join the branch- 
es of the inferior cardiac, or to unite with the cardiac 
branches of the left nerve of the par vagum. The 
others proceed behind the aorta, and enter into the 
common cardiac plexus. 

The second cardiac nerve of the left side may be 
called the Great Left Cardiac, and has a double 
origin as above mentioned. The principal branch 
in its composition arises from the lowest cervical 
ganglion, and passes behind the transverse portion 
of the subclavian artery. V¥here the inferior thyroid 
arises from the subclavian, this branch receives a 
considerable number of ramifications, which arise 
from the upper ganglion, and are interwoven with 
eacli other before they unite to it. It passes beliind 
the curve of the aorta, and terminates in the great 
cardiac plexus, which it particularly contributes to 
form. Here it is joined by many fibres from the par 
vagum. 



366 Plexus formed by the JVerves of the Heart, 
The Cardiac Plexus 

Is situated principally behind the curve of the aorta, 
at a small distance above the heart. It commences 
as high as the origin of the Arteria Innorainata, and 
extends downwards to the bifurcation of the pulmo- 
nary artery. 

As has been already mentioned, it is principally 
composed of branches from the middle cardiac nerve 
of the right side, and the inferior cardiac nerve of 
the left j but it receives branches from the superior 
cardiac of the left, and sometimes of the right side. 
Some fibres of the inferior cardiac of the right are 
also united to it. 

Many branches proceed from this plexus. 

A small number pass upon the aorta, and seem to 
enter into its texture.* 

Some of them also combine with the ramifications 
of the Par Vagum in the anterior pulmonary plexus. 

The majority proceed to the basis of the heart, 
near the origin of the pulmonary artery and the aorta, 
and constitute the proper nerves of that organ. They 
accompany the coronary arteries, and are so ar- 
ranged around them that, by some anatomists, they 
have been said to form plexuses, which have been 
denominated Coronary. 

The Sympathetic JVerve, as has been stated above, 
proceeds from the ganglion, called the Lower Cer- 
vical, or i\\Q First Thoracic, h^fove, the neck of the first 
rib. It continues to descend, in the same direction, 
along the spine, exterior to the pleura, to the inferior 
part of the thorax. Near the head of each rib it 
forms a ganglion, which unites with the intercostal 
nerve behind it, by two branches, and thus forms an 
indirect communication with the medulla spinalis. 

* It has been asserted, that some of the anatomists of Paris have 
traced these nerves on the aorta, to a great distance from the hearts 



iSympathetic JS'erve, audits Splanchnic Branches. 367 

From several of the uppermost of these ganglions., 
small twigs proceed to the pulmonary plexus, and 
also to the great trunk of the aorta, below the curve, 
forming a s^-^ecies of network, or plexus, upon it. 

From the ganglions near the heads of the fifth and 
sixth ribs, and from four or five of the ganglions 
which succeed them, small nerves arise, which pro- 
ceed downwards on the sides of the bodies of the 
Tertebrse, and unite into one trunk that is denomi- 
nated the Splanchnic JVerve, because it is distributed 
to the viscera of the abdomen. — This nerve proceeds 
behind the crus of the diaphragm, on its respective 
side, into the abdomen. A second and smaller nerve, 
of the same destination, called the Lesser Splanchnic 
J^erve, arises lower down, from two or three of the 
lowermost dorsal ganglions, and penetrates sepa- 
rately into the cavity of the abdomen : it then gene- 
rally divides into two branches, one of which unites 
to the great splanchnic nerve, and the other proceeds 
to the renal plexus y soon to be described. 

As soon as the great splanchnic nerve has entered 
the abdomen, it divides into many branches, which 
commonly form small ganglions on each side of the 
coeliac artery, but above it. These ganglions are 
generally contiguous ; but sometimes they are at a 
small distance from each other, and united by nerves. 
They are, however, commonly spoken of as one, and 
called the Semilunar Ganglion. They are of irregu- 
lar forms, and very different from each other in size, 
as well as form. Those formed by the splanchnic 
nerve on one side are sometimes different from those 
on the other. 

From this assemblage of ganglions proceed many 
small nerves, which are woven together so as to form 
a network denominated the Solar Plexus. 

This plexus is situated anterior to the spine and 
the crura of the diaphragm; behind the stomach, and 



368 ^arrangement of the JS'erves of the 

above the pancreas ; and is extended upon the coeliac 
and superior mesenteric arteries. Some ramifications 
from tlje par vagum and the phrenic also join it. 

The lower part of the solar plexus, which sur- 
rounds more immediately the coeliac artery, is termed 
the Cosliac Plexus. From it networks of nerves ex- 
tend upon the great branches of the artery to the or- 
gans which they go to. 

They extend to the stomach (although it is sup- 
plied by the par vagum) along the superior coronary 
or gastric branch of the coeliac ; and the fibres in their 
composition being spread upon the coats of the sto- 
mach, unite with the branches of the par vagum, 
which are also spread upon them. 

A similar network, denominated the Hepatic 
Plexus, extends upon the Hepatic Artery, and from it 
to the Vena Portarum ; and accompanies those ves- 
sels into the substance of the liver. It also sends 
branches to the biliary duct and gall bladder ; to the 
stomach by the arteria gastrica dextra ; and to the 
omentum. 

Tlie Sjplenic Artery is invested by a similar but 
smaller arrangement of nerves, denominated the 
Splenic Plexus. In its course to the spleen, this 
plexus sends some nerves to the pancreas ; and also 
to the stomach and .omentum, with the left gastric 
artery. 

The superior mesenteric artery is surrounded by a 
network, which extends to it directly from the solar 
plexus, and is the largest of all which proceed from 
that plexus. The Mese?ite?'ic Plexus at first nearly 
surrounds the artery, and proceeds with it between 
the laminae of the mesentery. In this course it sends 
branches, with the arteria colica dextra, to the trans- 
verse portion of the colon. Between the laminae of 
the mesentery, it sends ramifications with all the 
branches of the altery, to the small intestines ^ene 



Abdominal Viscera. 369 

rally ; to the coecum, and the right portion of the 
colon ; as well as to the mesenteric glands. 

From the lower part of the solar plexus a network 
proceeds, on the front of the aorta, to the inferior 
mesenteric artery, and surrounds it. Nerves from 
this plexus accompany the artery to the left portion 
of the colon and the rectum. Some of their ramifi- 
cations combine with those of the hypogastric plexus. 

The Emulgent*lrtery is attended by nerves, which 
are arranged like a network on its anterior and poste- 
rior surfaces, and are denominated the JRenal Plexus, 
They are derived from the solar plexus, and fre- 
c[uently contain small ganglions. They proceed 
with the artery to the fissure of the kidney, and are 
distributed with its different ramifications, in the sub- 
stance of the organ. 

Some branches pass from them to the renal gland 
with the capsular artery. 

Before the renal plexus arrives at the kidney, it 
sends off, from its inferior part, some new fibres, 
which, after joining some others from one of the lum- 
bar nerves, accompany the spermatic arteries, and are, 
therefore, called the Spermatic Plexus. In the male^ 
these fibres proceed through the abdominal ring, 
and many of them go to the testis, but they are fol- 
lowed with great difficulty, on account of their small 
size. 

In the female, they go to the ovary and the fallo- 
pian tube. 

From the great plexuses above, a small network 
continues downwards on the aorta, receiving fibres 
from the intercostals on each side ; at the great bifur- 
cation of the aorta it divides, and is joined on each 
side by many ramifications from the third lumbar 
nerves, which thus form a plexus of considerable 
extent, that sends nerves to the bladder, rectum, and 
vesiculae seminales in males ; and to the uterus and 

Vol. II. 47 



370 Tejinination of the Sympathetic A'^erve, 

vagina, as well as the bladder and rectum, in fe- 
males.* This is called the Hijpos;astric Plexus. 

The plexuses above mentioned are derived from 
the splanchnic nerve, which came off from the Sym- 
jpathetic in the thorax. 

The Sympathetic JVerve, after giving off the lesser 
splanchnic, is diminished in size, and approaches 
nearer to the bodies of the vertebrae. It passes 
through the crura of the diaphragm, and then pro- 
ceeds forwards and downwards upon the spine, be- 
tween the tendinous crura of the diaphragm and 
psoas muscle ; near the vena cava on the right side, 
and the aorta on the left. In this course, it gencr 
rally receives one or two small cords from the ante- 
rior branch of each of the lumbar nerves : these cords 
proceed downwards and forwards, between the bo- 
dies of the vertebrai and the psoas muscle, and a 
ganglion is generally formed at the place where they 
join the nerve. 

In its descent on the lumbar vertebrae, the Sym- 
pathetic sends off several nerves that unite to the 
network which descends on the aorta from the plexus 
above. After passing over the lumbar vertebrae, it 
descends into the pelvis, close to the sacrum, on the in- 
ner side of the great foramina: here it also forms gang- 
lions, and communicates with the sacral nerves, and 
likewise with the hypogastric plexus. It terminates 
on the OS coccygis, where its minute fibres join those 
of the opposite side. 

* Although the testicle receives nerves which are derived fronj 
the Sympathetic, the penis and other external parts of the organs 
of genei'ation do not : the nerves which accompany the pudic artery- 
being derived from those which unite to form the great Sciatic. 



SYSTEM OF ANATOMY 

PART XL 



OF THE ABSORBENT VESSELS.* 

The absorbent vessels are small transparent tubes, 
of a delicate structure, which exist in considerable 
numbers in almost every part of the body. 

Tliese tubes originate upon the surfaces of all the 
cavities of the body; and of the cellular membrane, 
in all the various parts into which it penetrates ; upon 
the internal surface of the stomach and the intestines ; 
and probably upon the skin. 

Those which oi'iginate in the Loiter Extremities 
and the Cavity of the Abdomen, unite and form a large 
trunk called the Thoracic Duct, which proceeds 
through the thorax, and terminates in the left Sub- 
clavian Vein, at its junction with the Internal Jugu- 
lar. Those of the Left Upper Extremity, the Left Side 
of the Head, and the contiguous parts, form a trunk 
which terminates in the same place. While the re- 
maining ahsorbents, or those of the Right Upper 
Extremity, and the Right Side of the Head, Sj^c. also 
form a trunk, which terminates in the corresponding 
part of the Right Subclavian Vein. 

The absorbent vessels of the middle size, which 

* Discovered at Leydcn in 1650, by Glaus Rudbeck, and at Co- 
penhagen in 1651, by Bartholine. — Ed. 



372 Structure of the Absorbent Vessels. 

arise from the union of the small vessels, and unite 
to form the larger, in their progress to these large 
vessels, pass through certain bodies which have been 
denominated Conglobate Glands, and may be consi- 
dered as appendages of the absorbent system. 

The absorbent vessels are composed of two coats, 
which are thin, but dense and firm, and also elastic. 
The coats of the thoracic duct may be separated 
from each other. The internal surface of the exte- 
rior coat is fibrous. The internal coat is a delicate 
but strong membrane. — There is great reason to be- 
lieve that the above mentioned fibres are muscular, 
or at least irritable : for the absorbent vessels have 
been observed, by Haller, to contract upon the ap- 
plication of strong sulphuric acid. They have also 
been observed to propel their contents with consider- 
able rapidity, by their own contraction, independent 
of pressure, or of motion communicated by any other 
body. 

Blood vessels are sometimes observable in the 
coats of the larger absorbents, in injected subjects. 
The vascularity of these tubes may also be inferred 
from the inflammation which frequently takes place 
in them. 

Nerves have not been traced into tlieir texture ; 
but the absorbents seem to be painful w'hen they are 
inflamed, and, therefore, it is probable that they are 
supplied with nerves. 

The absorbent vessels are very generally supplied 
with valves, which are much more numerous in some 
of them than in others ; and are different in their 
number, in the same vessels, in different subjects. 

Very frequently there are several valves in the 
course of an inch : sometimes a valve will not appear 
in the course of several inches. In the Thoracic Duct, 
the number of valves is very different in different 
subjects. These valves are folds or plaits of the in- 



Commencement of the Msorhenis, 373 

ternal membrane, and are of a semi-circular form. 
There are commonly two of them together, originat- 
ing from opposite sides of the vessel. 

The absorbents are generally somewhat dilated on 
the side of the valve which is next to their termina- 
tion, and this occasions their knotted appearance 
when tiiey are injected. The object of this valvular 
structure seems to be the prevention of retrograde 
motion of the contained fluid^ in consequence of la- 
teral pressure. 

Where the different trunks of the absorbents open 
into the veins, there are one or two valves to prevent 
the regurgitation of the blood into them. 

The valves of course prevent the injection of tlie 
branches of these vessels from their trunks. — In some 
animals the valves have sometimes been ruptured, or 
forced back ; and the absorbents have been injected 
in a retrograde direction. There are but two or 
three instances upon record where this has been 
practicable in the Human Subject. 

In consequence of the impracticability of injecting 
the small branches from the larger, the absorbent 
vessels cannot, generally, be demonstrated at their 
commencement^ or origin. It is, however, to be ob- 
served, that the Lacteals, or Absorbents of the Intes- 
tines f appear no way different from other absorbents; 
and they have been seen distended with chyle, from 
their commencement, in certain subjects who had 
died suddenly. Their origins have been described 
very differently by different observers. 

Mr. Cruikshank describes them as originating on 
the surfaces of the villi, by a number of very small 
radiated branches with open orifices; which branches 
soon unite to form a trunk. 

Lieberkuhn believed them to commence in the 
form of an ampullula. — Seepage 105 of this volume. 

The second Monro also believes that the absorb- 



374 Cohglobafe Glands. 

ents begin by very small tubes, with open orifices, iu 
several species offish.* 

It is stated by Dr. Soemmering, upon the authority 
of Haase, a German anatomist, that when mercury is 
forced backwards in the absorbent vessels of the foot 
'^^.\lA the heart, it has sometimes escaped on the sur- 
faces of those parts. The probable inference from 
these facts is, that those vessels originate by open 
orifices on the surfaces of the heart and foot. 

The bodies connected with the absorbent vessels, 
which are called Conglobate Glands, are generally 
of a roundish, or irregular oval form, and somewhat 
itattened. They are of various sizes, from two lines 
in diameter to more than twelve. Their colour is 
frequently whitish, but sometimes it is slightly in- 
clined to red. They are invested with a covering of 
cellular membrane, which appears like a membranous 
coat; and they are connected to the contiguous parts 
by a loose cellular substance. When the absorbent 
vessels connected with these bodies approach near 
to them, they divide into a number of ramifications, 
most of which enter into the substance of the gland, 
while some of them run over it. On the opposite 
side of the gland a number of branches go out, which 
unite and form trunks similar to those which entered 
the gland. The vessels which enter the gland are 
called Vasa Inferentia, and those which go out of 
it Vasa efferentia. 

These vessels are generally much convoluted in 
the substance of the glands, so that those bodies 
sometimes appear like a mere convolution of absorb- 
ent vessels. There has been much diversity of senti- 
ment respecting the structure of these organs. f 

* See his work on the Structure and Physiology of Fishes, p. 34. 

t Mr. Abernethy states, that the mesenteric gland of the Whale 
consists of large spherical bags, into which a number of the lacteals 
open. Numerous blood vessels are ramified on the surfaces of these 



Fluid contained i?i the Msorbents. 375 

The absorbent vessels, in the different parts of the 
body, generally contain fluids resembling those Avhich 
are found in those parts. Mr. Hevvson opened the 
large absorbents in many living animals of different 
kinds, and found that they contained a transparent 
fluid, which coagulated when exposed to the air. 

The arrangement of these vessels resembles that 
of the veins in several respects. Many of them are 
superficial ; but there are also deep-seated absorb- 
ents which accompany the blood vessels. 

cysts ; and injection passes from them into the cyst. He also found 
cells in the glands of the absorbent vessels, in the groin and t.he 
axilla of the horse. — See Philosophical Transactions, for l!^W£', 
Part I. 



CHAPTER I. 

OF THE ABSORBENTS OF THE LOWER EXTREMITIES, 
THE ABDOMEN, AND THE THORAX. 

Under this head are arranged the ramifications 
of all the vessels which unite to form the Thoracic 
Duct. 

SECTION I. 

Of the Absorbents of the Lower Extremities. 

These absorbents, like the veins, are superficial 
and deep-seated. The Superficial lie in the cellu- 
lar membrane, very near the skin ; and form an irre- 
gular network which extends over the whole limb. 
They are, however, most numerous on the internal 
side. 

The Deep-seated accompany the arteries like the 
veins, and there are two at least to each artery. 

The Superficial Msorbents 

Have been injected from the toes so as to form a 
network, which occupies the upper surface of the 
foot. They have also been injected in a similar 
manner on the sole. Those on the upper surface of 
the foot generally proceed upward on the anterior 
and inner side of the leg ; but some of them pass on 
the external side of it. Those on the sole are con- 
tinued on the back of the leg, but communicate very 
frequently with the anterior vessels. Some of the 
absorbents from the outside of the foot and leg enter 
into some of the popliteal glands, soon to be de- 
scribed ; but they are not numerous ; and the princi- 
pal number continues up to the glands of the groin. 



Msorbents of the Lower Extremity, 377 

The absorbents which originate on the surface of 
the thigh, as well as those which pass over it from 
below, incline gradually along the anterior and pos- 
terior surface, to the internal «ide of it ; on which 
they proceed, in great numbers, and very near to 
each other, to the inguinal glands. Superficial ab- 
sorbents proceed also from the buttock and lower 
part of the back, from the lower part of the abdo- 
men, the perineum, and the exterior of the genital 
organs, to these glands. 

The Beep-seated Msorhents 
Are named from the arteries they accompany. 

The Anterior Tibial Absorbents. 

The anterior tibial artery is generally attended 
by one which comes with it from the sole, and by 
another which commences on the upper surface of 
the foot. The first mentioned absorbent continues 
with the artery. The last, often passes through an 
aperture in the interosseal ligament, about one third 
of the distance from the ankle to the knee, and ac- 
companies the fibular artery, while the anterior tibial 
artery is joined by other absorbents about the same 
place. In some instances a small absorbent gland 
occurs in this course, at a short distance below the 
knee. 

The Posterior Tibial Absorbents 
Have been injected from the under side of the toes. 
They accompany the ramifications on the sole of the 
foot ; and after uniting, continue with the main trunk 
up the leg, where they enter the popliteal glands. 

Tlie Peroneal Absorbents arise also from the sole 
of the foot, and its external side. They accompany 
the peroneal artery, and terminate in the })opliteal 
glands, which receive also the absorbeots from the. 
knee and ham. 

Vol. II. 48 



378 Absorbents of the Lower Extremity. 

From these glands four or five absorbent vessels 
proceed, which accompany the great blood vessels 
of the lower extremity ; and, proceeding with themi 
through the aperture in the tendon of the adductorsy 
continue upwards until they enter some of the glands 
of the groin. 

The glands of the ham and groin, which are so 
intimately connected with the absorbents of the lower 
extremity, are very different from each other. 

The Popliteal Gla7icls, or those of the Ham, are 
but three or four in number, and very small in size. 
They are generally deep-seated, and very near the 
artery. 

The Inguinal Glands vary in number, from eight 
to twelve or more. They are superficial and deep- 
seated. The superjieial communicate principally 
witli the superficial absorbents. The lowermost of 
them are at some distance below Poupart^s ligament, 
and the uppermost are rather above it. They are 
exterior to the fascia of the thigh. Their number is 
generally six or eight, while that of the deep-seated 
is but three or four. 

The superficial absorbents from below, approach 
very near to each other, and enter these glands. 
They are commonly distributed among three or four 
of the lowermost ; but some of them pass by these, 
and proceed to one that is higher up ; and some- 
times there are absorbent vessels which pass to the 
abdomen without entering into any of the glands of 
the groin. 

The deep-seated absorbents pass into the deep- 
seated glands, which, as has been already observed, 
are but few, and lie very near the artery under the 
fascia of the thigh. The two sets of glands are 
connected to each other by many absorbent vessels 
that pass between them. The vessels which finally 
go out of these glands are considerably less in num- 



Inguinal and External Iliac Glands. 379 



"a 



ber than those which enter into them. They pro- 
ceed under Poupart's ligament, and, in some in- 
stances, a large proportion of them passes through 
three glands which lie below this ligament, and are 
often so arranged, that they lie on each side of the 
great femoral vessels, and above them. One very 
frequently is found on the inside of the femoral vein, 
in the vacuity between it and the internal part of the 
ligament. All the absorbents of the lower extre- 
mity, however, do not enter these glands. Some 
pass along the great vessels and enter other glands 
near the margin of the pelvis. Some also descend 
a short distance into the pelvis, and unite with ves- 
sels that are passing from the pelvis to the plexus 
and the glands that surround the external iliac. 

The absorbents which proceed from the glands 
last mentioned, joined to those which pass under 
Poupart's ligament, without entering these glands, 
and some which come from the pelvis, form a large 
plexus, which almost surrounds the external iliac 
vessels, and contains many glands. 

Th&at External Iliac Glands vary in their number 
from six to ten or twelve. They lie on the side of 
the pelvis, in the course of the external iliac vessels, 
and some of tliem are of considerable size. These 
glands and the plexus of absorbents, extend in the 
track of the iliac vessels, to the first lumbar vertebra. 
In this course they are joined by the plexus which 
comes from the pelvis ; and soon after they arrive at 
the Lumbar Glands^ which form a very large assem- 
blage, that extends from the bifurcation of the aorta 
to the crura of the diaphragm. 

These glands lie irregularly, on the aorta, the 
vena cava, and the lumbar vertebrai. Most if not all 
the absoibents above mentioned pass through some of 
them ; and from the union of these aI)sorbents, some 



380 Msorhents of the Testicles, ^^c, 

of the great branches, which unite to form the thora- 
cic duct, are derived. 

In this course from the thigh to the lumbar glands^ 
these absorbent vessels are joined by several others. 
The Superficial Absoi^bents of the scrotum commonly 
enter into the upper inguinal glands, and thus unite 
to the great body of absorbents. 

The Absorbents of the Testicles originate in the 
body, and the coats of the testicle, and in the epidi- 
dymis, and are remarkably large and numerous. 
They proceed along the spermatic cord, through the 
abdominal ring, to the lumbar glands. These ves- 
sels are remarkable for the little communication they 
have with each other. 

The Deep-seated Absorbents of the Scrotum accom- 
pany the absorbents of the testicle to the luubar 
glands ; but those which are superficial enter the 
upper inguinal glands. 

The Absorbents of the Penis are also deep-seated 
and superficial. The deep-seated arise from the 
body of the penis, and accompany the internal pudic 
artery into the pelvis. The superficial absorbents 
arise from the prepuce, and pass along the dorsum 
of the penis. There are frequently several trunks 
which receive branches from the lower surface of 
the penis in their course. At the root of the penis 
they generally separate to the right and left, and pass 
to the glands on the respective sides. 

In females, the absorbents of the interior of the 
clitoris accompany the internal pudic artery. Some, 
which arise about the vagina, pass through the ab- 
dominal ring with the round ligament; and others 
proceed to the inguinal glands. 



Absorhents of the Pelvis and the Kidneys., 38i 

SECTION II. 

Of the Mswle^its of the Abdomen and Thorax. 

The Abso?'bents of the lower portions of the pa- 
rietes of the Abdomen and the Pelvis unite into trunks 
that follow the epigastric, the circumflex and the 
iliac, as well as the lumbar and sacral arteries, &c. 
They proceed to some of the glands which are in the 
groin ; or in the external iliac, the hypogastric, or 
grt)rae of the contiguous plexuses. 

The Absoi'bents of the Womb are extremely nume- 
rous; and, in the gravid state, are very large. Those 
which are on the neck and anterior part of the uterus, 
join the hypogastric plexus. Those which are on 
the posterior part of the body, accompany the sper- 
matic vessels. 

The Absorbents of the Bladder pass to small glands 
on its lateral and inferior parts, and finally join the 
hypogastric plexus. 

The Absorbents of the Rectum are of considerable 
size. They pass through glands that lie upon that 
intestine, and unite with the lumbar plexus. 

The Absorbents of the Kidney are superficial and 
deep-seated. They are very numerous, but, in a 
healthy state of the parts, are discovered with diffi- 
culty. Cruikshank describes them as they appeared, 
filled with blood, in consequence of pressing upon 
the kidney when its veins were full of blood. Mas- 
cagni did not inject the superficial vessels with mer- 
cury ; but describes them as they appeared when 
filled with colourless size, after he had injected the 
blood vessels of the organ with the coloured fluid. — 
The deep-seated absorbents pass out of the fissure 
of the kidney with the blood vessels, and unite with 
the superficial : they proceed to the lumbar plexus, 
and pass into diff'erent glands. 



382 Lacteals, or Absorbents of the Intestines. 

Absorbent vessels can be proved to proceed from 
the pelvis of the kidney, and the ureters, by artifices 
analogous to those above mentioned. 

The Gkmdtdx Renales are also supplied with ab- 
sorbents, which are numerous in proportion to the 
size of the organs. They commonly join those of the 
kidney. 

The Absorbents of the Intestines 

Have generally been called LA.CTEALS, from the 
w hite colour of the chyle which they contain : but 
there seems no reason for believing that they are dif- 
ferent in their structure and nature from the absorb- 
ents in other parts of the body. A small number of 
them appear as if they formed a part of the structure 
of the intestines, and originated from their external 
surface, as they do in other parts of the abdomen ; 
while the principal part of them are appropriated to 
the absorption of the contents of the cavity of the 
intestines. 

The first mentioned absorbents run between the 
muscular and peritoneal coats, and proceed for some 
distance lengthways on the intestine, while the others 
proceed for some distance within the muscular coat, 
with the arteries ; and after passing through it, con- 
tinue between the laminae of the mesentery. 

Branches of these diiferent absorbents are fre- 
quently united in one trunk ; so as to prove that there 
is no essential difference between them. 

The absorbents which come from tlie internal sur- 
face of the intestines commence in the villi. The 
manner in which they originate has been the subject 
of considerable inquiry, as has been stated in the 
account of the intestines.* 

The lacteals or absorbents of the intestines are 

* See page 105. 



Lacteals, or Absorbents of the Intestines, 383 

very numerous. They pass between the laminse of 
the mesentery to glands which are also seated be- 
tween those laminse. The number of these glands 
is very considerable,* and they are various in size 
— some being very minute, and others eight or ten 
lines in diameter. They are generally placed at a 
small distance from each other, and are most nume- 
rous in that part of the mesentery which is nearest 
to the spine. They are almost always at some dis- 
tance from the intestines. They appear to be pre- 
cisely like the absorbent glands, in other places. 

These absorbent vessels, in their course frequent- 
ly divide into branches ; which sometimes go to the 
same gland, sometimes to different glands, and some- 
times unite with other absorbent vessels. As they 
proceed, they frequently enlarge in size. Wlien 
they have arrived near the spine, they frequently 
form three or four trunks, and sometimes one or two ; 
■which proceed in the course of the superior mesen- 
teric artery, until they have arrived near to the aorta. 
Here they either pass into the tlioracic duct, or de- 
scend and join the trunks from the inferior extremi- 
ties, to form the thoracic duct. The absorbents of 
the great intestines are not equal in size to those of 
the small ; but they are numerous. They enter into 
glands, which are very near, and in some places, in 
contact with the intestine; and are commonly very 
small in size. The vessels which arise from the 
caecum, and the right portion, as well as the arch of 
the colon, unite with those of the small intestines ; 
while the vessels from the left side of the colon, and 
the rectum, proceed to the lumbar glands. 

The absorbents of the intestines are frequently 
injected with mercury ; but the injection does not 
proceed to their termination with so much facility as 

* They have been estimated between 130 and 150. 



384 Absorbents of the Stomach. 

it does in other vessels of tiie same kind. They have, 
however, very often been seen in animals, who were 
killed for the purpose after eating milk ; and in se- 
veral human subjects who died suddenly during 
digestion. — The description of the origin of the 
lacteals, quoted in page 108, from Mr. Cruikshank, 
was taken from a subject of this kind, of which an 
account is given in his work on the absorbing ves- 
sels, p. 59. 

It is worthy of note, that in several instances, in 
which the lacteals were thus found distended with 
chyle, the glands in the mesentery were also uniform- 
ly white. 

The Absorbents of the Stomach 

Are of considerable size, and form three divisions. 
The vessels of the first set appear upon both sides 
of the stomach, and pass thr jugh a few glands on 
the small curvature, near the omentum minus. — 
From these glands they proceed to others, which 
are larger, and which also receive some of the deep- 
seated absorbents of the liver. The vessels from 
these glands pass to the thoracic duct, near the 
origin of the coeliac artery. The second arise also 
on both sides of the stomach, and pass to the left 
extremity of the great curvature to unite with the 
absorbents of that side of the great omentum. They 
then proceed with the lymphatics of the spleen and 
pancreas, to the thoracic duct. The last set pass off 
from the right extremity of the great curvature, and 
unite also with absorbents from the right portion of 
the omentum. They proceed near the pylorus, and 
go to the thoracic duct, with some of the deep-seated 
absorbents of the liver. 

Altliough the absorbents of the stomach are deep- 
seated, as well as superficial, it is a general senti- 
ment, that they do not contain chyle in the humaa 



Absorbents of tJie Liver. 385 

subject ; notwithstandino; chyle lias been found in 
the abs(>ri)t^nts on the stomach of dogs, and some 
other ariinaals. It ought, hou ever, to be remember- 
ed, that Sabatier has, in some instances, seen white 
lines on the stomach, which he supposed to be 
lacteals. 

The Absorbents of the Liver 

Are especially interesting, because they have been 
more completely injected than those of any other vis- 
cus. They are deep-seated and superficial. The 
superficial it has been already observed admit of in- 
jection in a retrograde direction, and, therefore, can 
be exhibited most minutely ramified. They commu» 
nicate freely with each other, and also with the deep- 
seated vessels, by their small ramifications ; so that 
the whole gland has been injected from one large 
vessel. 

The gland is so large, that the absorbents of the 
s'lperior and inferior surfaces proceed from it in dif- 
ferent directions. 

A large absorbent is generally found on the sus- 
pensory ligament. This is formed by the union of 
a great many branches that arise both on the right 
and left lobes, but principally on the right. It often 
passes through the diaphragm at an interstice wiiich 
is anterior to the xiphoid cartilage, and then proceeds 
through glands on the anterior part of the pericar- 
dium. 

Several absorbents proceed to the lateral ligaments 
on each side, and then pass through the diaphragm. 
Some of these branches return again into the abdo- 
men, and the others generally run forwards in the 
course of the ribs, and join those w hich passed up 
from the suspensory ligament. The trunk, or trunks, 
formed by these vessels, either pass up between the 
laminic of the mediastinum, and terminate in the up- 

Vol. II. 49 



S86 Absorbents of the Liver and Spleen. 

per part of the thoracic duct ; or they accompany the 
internal mammary arteries, and terminate on the left 
side in the thoracic duct, and on the right in the 
trunk of the absorhents of that side. 

The Ahsorbeyits on the. concave side of the Liver 
are as numerous as those on the convex side; they 
are also very abundant on the surface of the gall 
bladder. The greatest part of them join the deep- 
seated vessels. 

The Deep-seated Absorbents proceed in considera- 
ble numbers from the interior of the liver through the 
portsa. They accompany the biliary ducts and the 
great blood-vessels of the organ ; and, after passing 
through several glands, near the vena portarura, ter- 
minate in the thoracic duct, near the commencement 
of the superior mesenteric artery. 

Mascagni states, that the absorbents of the liver 
will be distended, by injecting warm water into the 
biliary ducts, or the vena portarura. 

He also observes, that in those preparations in 
which the superficial vessels are completely injected, 
in the retrograde direction, the peritoneal coat of the 
liver appears to be composed entirely of absorbent 
vessels ; and to be connected to the membrane within, 
by many filaments which are also absorbent vessels. 

The Jibsorbeyits of the Spleen 

Are composed of superficial and deep-seated vessels; 
but they differ greatly from those of the liver, in this 
respect, that the superficial vessels are remarkably 
small in the human subject. 

Mascagni however asserts, that when the blood- 
vessels of the spleen are injected with size, coloured 
with vermilion, these absorbents will be filled with 
colourless size. 

In the spleen of the calf the superficial absorbents 
are remarkably large. 



Msorbents of the Pancreas. — Thoracic Duct. 387 

In the human subject the superficial absorbents of 
the spleen proceed from the convex to the concave 
surface, and there communicate with the deep-seated 
absorbent-*, which proceed from the interior of the 
organ with the blood-vessels. 

These Deep-seated Ahsorhents are very numerous, 
and also large. They accompany the splenic arte- 
ry ; and in their course pass through many glands, 
some of which are said to be of a dark colour. The 
glands lie on the splenic artery, at a short distance 
from each other. The absorbents of the spleen re- 
ceive the absorbents of the pancreas in (heir course^ 
they unite with the absorbents of the stomach and the 
lower surface of the liver, and pass witii them to the 
thoracic duct. 

Little has been latterly said by practical anato- 
mists respecting 

The Absorbents of the Pancreas. 

Mr. Cruikshank once injected them in the retrograde 
direction; he found that they came out of the lobes 
of the pancreas in short branches like the blood ves- 
sels, and passed at right angles into the absorbents 
of the spleen, as they accompanied the artery in the 
groove of the pancreas. 

THE THORACIC DUCT,* 

Or common trunk of the absorbent system, is formed 
by the union of those absorbent vessels which are 
collected on the lumbar vertebrae. 

These vessels, as it has been already observed, 
are derived from various sources, viz. 

The Lower Extremities ; the lower part of the 
Trunk of the Body ; the Organs of Generation ; the 

* First discovered by Eustachius in the horse, 1 J64, but he con- 
siders it a vein for the nourishment of the thoracic viscera. Ed. 



388 Commencement of the Thoracic Dud. 

Intestines, with the other Viscera of the abdomen 
and pelvis, except a part of the liver. Their num- 
ber is proportioned to tlie extent of their origin : for, 
with the numerous glands appropriated to them, 
they form the largest absorbent plexus in the body, 
and are spread over a considerable portion of the 
aorta and the vena cava. 

The manner in which these vessels unite to form 
the thoracic duct, is very different in different sub- 
jects ; but in a majority of cases it originates imme- 
diately from three vessels, two of which are the 
trunks of the absorbents of the lower extremities, 
and the other is the common trunk of the lacteals 
and the other absorbents of the intestines. 

These vessels generally unite on the second or 
third lumbar vertebrae; and, in some instances, the 
trunk which they form dilates considerably, soon af~ 
ter its commencement; in consequence of which it 
was formerly called the RECEPTACLE of the 
CHYLE. At first it lies behind the aorta, but it 
soon inclines to the right of it, so as to be behind the 
right cms of the diaphragm. In the thorax, it ap- 
pears on the front of the spine, between the aorta 
and the vena azygos, and continues between these 
vessels until it has arrived at the fourth or third dor- 
sal vertebra. It then inclines to the left, and pro- 
ceeds in that direction until it emerges from the 
thorax, and has arisen above the left pleura, when 
it continues to ascend behind the internal jugular, 
nearly as high as the sixth cervical vertebrae : it then 
turns downward and forward, and, after descend- 
ing from six to ten lines, terminates in the back part 
of the angle formed by the union of the left internal 
jugular with the left subclavian vein. Sometimes, 
after rising out of the thorax, it divides into two 
branches, which unite before they terminate. Some- 
times it divides, and one of the branches terminates 



Absoi'hents of the Lungs. 389 

at the above mentioned angle, and the other in the 
subclavian vein, to the left of it. 

The orifice of the thoracic duct has two valves, 
which effectually prevent the passage of blood into 
it from the vena cava. 

There are sometimes slight flexures in the course 
of the duct ; but it geuerally inclines to the left, in 
the upper part of the thorax, as above mentioned ; 
and is then so near the left lamina of the mediasti- 
num, that if it be filled with coloured injection, it 
can be seen through that membrane, when the left 
lung is raised up and pressed to the right. 

The duct sometimes varies considerably in its dia- 
meter in different parts of its course. About the mid- 
dle of the thorax it has often been found very small. 
In these cases it generally enlarges in its progress 
upwards, and is often three lines in diameter, in its 
upper part. Many anatomists have observed it to 
divide and to unite again, about the middle of the 
thorax. 

•Absorbents of the Lungs. 

The absorbents of the lungs are very numerous^ 
and, like those of other viscera^ are superficial and 
deep-seated. 

The large superficial vessels run in the interstices 
between thelobuli, and therefore form angular figures 
of considerable size. In successful injections, the 
vacancies within these figures are filled up with 
small vessels, and the whole surface appears minute- 
ly injected. 

Mascagni observes, that the superficial vessels are 
very visible when any fluid has been effused into 
the cavity of the thorax ; or when warm water is in- 
jected, either into the blood vessels of the lungs, or 
the ramifications of the trachea. Cruikshank de- 
monstrated them by inflating the lungs of a still bom 



390 Absorbents of the Lungs^ 

child ; in which case the air passes rapidly into 
them. 

The deep-seated absorbents accompany the blood- 
vessels and the ramifications of tlie bronchise. They 
pass to the dark coloured glands, which are situat- 
ed on the trachea at its bifurcation; and on those 
portions of the bronchiae which are exterior to the 
lungs. The injection of the absorbents, Avhich pass 
to and from these glands, seems to prove that they 
are of the same nature with the absorbent glands in 
general, notwithstanding their colour. They are 
numerous, and they vary in size ; from a diameter 
of two lines, to that of eight or ten. 

From these glands, some of the absorbents of the 
left lung pass into the thoracic duct, while it is in 
the thorax, behind the bifurcation of the trachea ; 
others proceed upwards and enter into it near its ter- 
mination ; while those of the right lung terminate in 
the common trunk of the absorbents of the right 
side. 



CHAPTER II. 

OF THE ABSORBENTS OF THE HEAD AND NECK ; OF 

THE UPPER EXTREMITIES, AND THE UPPER 

PART OF THE TRUNK OF THE BODY. 

The absorbents from the various parts of the bead 
pass through glands, which are situated on the neck, 
or the lower part of the head. Those on the head 
are the least numerous, and also the least in size. — 
Some of them, which are generally small, lie about 
the parotid gland. Several of them, which are also 
small, are on the occiput, below and behind the 
mastoid process. Sometimes there are two or three 
on the cheek, near the basis of the lower jaw, about 
the anterior edge of the masseter muscle. Below the 
lower jaw, in contact with the sub-raaxillary gland 
and anterior to it, there are always a number of these 
glands, which are generally small, but often swelled 
during infancy. 

The Glands on the J\/eck are the most numerous. 
Many of them are within the sterno- mastoid muscle, 
and accompany the internal jugular vein and the 
carotid artery down to the first rib. Many also lie 
in the triangular space between the sterno-mastoid 
muscle, the trapezius, and the clavicle ; therefore it 
has been truly said that the glands of the neck are 
more numerous than those of any other part, except 
the mesentery. They are frequently called Glandulx 
Concatenatae. It has already been mentioned that 
the various absorbents, which are connected with 
these glands, unite on each side into a trunk, which 
on the left passes into the thoracic duct, and on the 
right into the common trunk of the absorbents of 
that side. 



39IS Absorbents of the Head and JVeck, 

SECTION I. 

Of the tdbsorhents of the Head and JVeck, 

There is the greatest reason to believe that the 
brain and its appendages are supplied with absorb- 
ents like the other parts. Some of these vessels 
Iiave been discovered in the cavity of the cranium ; 
but very little precise information has as yet been 
obtained, respecting the extent, or arrangement of 
the absorbent system, in this part of the body. 

The absorbents on the exterior of the head are as 
numerous as in other parts of the body. On the 
occiput they pass down, inclining towards the ear, 
and continue behind it to the side of the neck ; be- 
hind the ear they pass through several glands. — 
From the middle or temporal region of the cranium, 
they pass with the carotid artery before the ear, and 
enter some small glands that lie on the parotid ; from 
which they continue to the neck. 

They are on every part of the face, and unite, so 
that their principal trunks, which are very numerous, 
pass over the basis of the lower jaw, near the facial 
artery. They enter into glands, which are also very 
numerous, immediately under the jaw, or which are 
sometimes to be found on tlie cheek, at the anterior 
edge of the masseter muscle. All the absorbents of 
the exterior part of the head pass to the glands oa 
the side of the neck, already described. 

Those from the interior of the nose accompany 
the raraiilcations of the internal maxillary artery, and 
proceed to glands behind the angle of the lower jaw; 
into which glands also enter the absorbents of the 
tongue and inner parts of the mouth. 

The absorbents of the thyroid gland, on the left 
side, pass down to the thoracic duct ; those on the 
right^ unite to the trunk of the absorbents pn that 



Absorhents of the Hand and Arm. 393 

side, near its termination. It has been remarked 
that they can be readily injected, by thrusting the 
pipe into the substance of the gland. 



Section ii. 

Of the Absorbents of the Arm and Upper Part of the 
Trunh. 

The absorbents of the arm are superficial and deep^ 
seated, like those of the lower extremity. 

The superficial absorbents have been injected On 
the anterior and posterior surfaces of the iiogers and 
the thumb, near their sides. On the back of the 
hand they are very numerous, and increase consi- 
derably in their progress up the fore arm. As they 
proceed upwards, they incline towards the anterior 
surface of the fore arm ; so that by the time they have 
arrived at the elbow, almost all of them are on the 
anterior surface. The absorbents on the anterior 
part of the hand are not so numerous as those on the 
back. Sometimes there are digital branches from 
the fingers, and an arcus in tlie palm ; but tliis bow 
is not formed by one large absorbent, analogous to 
the ulnar artery. On the contrary, its two extremi- 
ties are continued over the wrist, and pass on the 
fore arm like the absorbents. 

At the elbow, some of them often pass into one or 
two small glands, which are very superficial ; but 
the whole of the absorbents, somewhat reduced in 
number, as some of them unite together, pass along 
with the blood vessels into the hollow of the arm pit ; 
where they enter the axillary glands. There are 
generally one or more vessels which pass in the 
course of the cephalic vein, between the pectoral and 
the deltoid muscle, and enter into some of the glands 
under the clavicle. 

Vol. H, 50 



394 Absorbents of the Upper Part of the Trunk. 

There are almost always several glands in and 
near the axilla. Some of them are very near the 
great blood vessels ; sometimes one or more of them 
are much lower; sometimes they are to be found 
under the pectoral muscle. They are commonly not 
so large as those of the groin, and are surrounded 
with fat. 

The deep-seated absorbents originate also at the 
iingers, and soon accompany the branches of the ar- 
teries. Those which attend the radial artery, origi- 
nate on the back of the hand, and also in the palm, 
"where they are associated with the arcus profundus. 
They go up with the radial artery to the elbow, and 
sometimes pass through a small gland about the 
middle of the fore arm. 

Those which attend the ulnar artery, commence 
under the aponeurosis palmaris, and go with the ar- 
tery to the elbow ; at the bend of the elbow they are 
generally joined by one or more, which accompany 
the interosseal artery ; there they unite, so as to form 
several trunks which pass up to the axillary with 
the humeral artery. They sometimes pass through 
one or two glands, which are near the elbow ; and 
they receive in their course, deep-seated branches 
from the muscles on the humerus. 

The absorbents from the anterior and external 
part of the thorax, and the upper part of the abdo- 
men, also proceed to the axilla, and enter into the 
glands there ; those which are deep-seated, joining 
the deep-seated vessels. The absorbents of the 
mammae pass to the same glands ; and when they 
are affected with the virus of cancer, can often be 
perceived, in their course, in the living subject. 

The absorbents of the uppermost half of the back, 
and those of the back of the neck, go likewise to the 
axilla. 

Thfe^^absorbent vessels; collected from these vari- 



Facts relatmg to Cutaneous Jlbsorption, 395 

rious sources, proceed from the exterior to the inner- 
most glands, but with a considerable diminution of 
their number ; they accompany the subclavian vein, 
and are reduced to one or two trunks, that gene- m 
rally unite before their termination. On the left ' 
side^ the absorbents of the head and neck generally 
open into the thoracic duct, as has been already ob- 
served ; and those of the left arm also open into the 
thoracic duct, or into the subclavian vein very near 
it. On the right side the absorbents from each of 
these parts empty into the common trunk; which 
often is formed by the union of large vessels, from 
four sources ; viz. the Head, the Thyroid gland, the 
right Arm, and the right cavity of the Thorax, &c. 
The diameter of the trunk is very considerable ; but 
it is often not more than half an inch in length. It 
generally opens into the right subclavian vein, at 
the place where it unites to the right internal ju- 
gular. 

Two respectable physiologists of Europe (M. Seguin, of 
Paris, and the late Dr. Currie, of Liverpool) have 
doubted whether absorption takes place on the exter- 
nal surface of the skin.* This question has been exa- 
mined in a very interesting maujjer by several gra- 
duates of the University of Pennsylvania, who chose 
it for the subject of their inaugural theses; viz. Drs. 
Rousseau, Klapp, Daingerfield, Mussey, and J. Brad- 
ner Stewart. 

The three first of these gentlemen state, that when spirit 
of turpentine, and several other substances which are 
commonly supposed to be absorbed by the skin, were 
applied to it in a way which prevented their volatile 

• I believe that M. Seguin's Memoir on this subject was read to 
the Academy of Sciences a short time before the meetings of that 
body were suspended. It was published by M. Fourcroy, in La 
Medicine Eclair^e par les Sciences Physiques, vol. iii. An extract 
from M. Foiircroy's publication may be seen in the 19th chapter of 
the first volume of Dr. Currie's " Medical Reports on the Effects of 
Water," Wc, in which is also contained a statement of the Doctor's 
own experiments and reflections. 



S96 Experiments of K, Boerhaave and J. Hunter. 

parts from entering the lungs bj respiration, no ab- 
sorption took place. But wlien they inspired air im- 
pregnated with exhalations from these substances, they 
perceived satisfactory proofs that the exhalations en- 
tered the system. From these facts they inferred that 
when those articles entered the body by absorption, 
they were taken in by the lungs, and not by the exter- 
nal surface. 

On the other hand, the two gentlemen last mentioned. 
state that after immersing themselves in a bath con- 
sisting of a decoction of rhubarb, of madder, or of tur- 
meric, their urine became tinged with these sub- 
stances. They also assert that the colouring matter 
of these different articles is not volatile; and, there- 
fore, could not have entered the lungs during the ex- 
periments.* 

The statement in page 374, from Dr. Soemmering, that 
when mercury is injected backxvards in the absorbent 
vessels which originate on the foot, it will sometimes 
appear in small globules on the skin of the foot, has 
an important connexion with this subject.! 



About the middle of the last century, it was generally 
believed by anatomists, that absorption was performed 
by the veins. This doctrine seemed to be established 
by the experiments of Kaaw Boerhaave, which are re- 
lated, with many other interesting statements, in his 
work entitled "Perspiratio Dicta Hippocrati," &c., 
published at Leyden, in 1738. In these experiments 
it appeared to the author, that when the stomach of a 
dog was emptied of its contents, and filled with warm 
water, immediately after death, the water passed into 
the minute ramifications of the veins of the stomach, 

* The Thesis of Dr. Rousseau wns published in 1800. Those of 
Drs. Klapp and Daingerfield in J805. Dr Mussey published in the 
Third Supplement to the Medical and Physi( al Journal of Dr. Bar- 
ton, in 1809. Dr. Stewart published in 1810 Additional observa- 
tions by Drs. Klapp, Rousseau and Smith, are published in the Phi- 
ladelphia Medical Museum, vol. i. new series. 

I Since the publication of the first volume, the author has enjoyed 
the advantage of consulting a translation, in manuscript, of some 
parts of the German edition of Dr. ^oemmering's valuable work 
on the Structure of the Human Bodv. 



Experiments of Magendie and Delile. 397 

and from them to the vena portarum, and ultimately 
to the heart, in large quantities. 

This account appears to be disproved by some experi- 
ments of the late John Hunter, made about twenty 
years after, and published in the Medical Commenta'- 

ries of Dr. William Hunter, Part I. Mr. Hunter's 

experiments have been considered as establishing the 
fact, that absorption (in the intestines at least) is per- 
formed exclusively by the lacteals, or proper absorbent 
vessels, and not at all by the veins. Kaaw Boer- 
have is of course supposed to have been mistaken; 
and Mascagni, who has repeated his experiment, re- 
fers the appearance of water in the veins to transuda- 
tion, through the coats of the intestines; which he has 
observed to take place to a great degree. 

In the year 1809, a memoir was presented to the na- 
tional institute of France by Messrs. Magendie and 
Delile, which contains an account of some experiments 
that have an important relation to the above mentioned 
subject.* — The authors being greatly surprised at the 
rapidity with which the poison of Java, &c. appeared 
to enter the sanguiferous system, instituted a series 
of experiments to determine whether these substances 
proceeded to that system by the circuitous route of the 
absorbent vessels, or by the shorter course of the veins. 
Two of their experiments are especially interesting. 
They made an incision through the parietes of the ab- 
domen of a living dog, who had eaten a large quantity 
of meat some hours before (that his lacteals might be 
visible from their distension with chyle,) and, draw- 
ing out a portion of the small intestine, they applied 
two ligatures to it, at the distance of five inches from 
each other. The portion of intestine between these 
ligatures was then separated by incision from the rest 
of the intestinal tube, and all the lacteals, blood ves- 
sels, &c. which passed to and from it, were divided, 
except one artery and a vein. A considerable length 
of this artery and vein were detached from all the sur- 
rounding parts, so that the authors supposed these 

* The title of the paper is a " Memoir on the Organs of Absorption 
in Mammiferous Animals.'" A translation of it was published in the 
Medical and Philosophical Register of New Yoj'k, and in several 
/((ther periodical works. 



398 Experiments of Magendie and Delile, 

vessels to form the only connexion between the por- 
tion of the intestine and the rest of the body. Into the 
cavity of the intestine, which was thus circumstanced, 
they introduced a small quantity of the poison, and, to 
their astonishment, it produced its fatal effects in the 
same manner it would have done if it had been intro- 
duced into the intestine while all its connexions with 
the body were entire. This experiment, they assert, 
was repeated several times, without any difiference in 
the result. 

After several other experiments, they finally separated 
the thigh from the body of a living dog in such a man- 
ner that the crural artery and vein were left undivided. 
A quill was then introduced into the artery, and two 
ligatures were applied to fix it round the quill. The 
artery was then divided between the two ligatures. The 
vein was managed in the same manner. There was, 
therefore, no communication between the limb and the 
body, except by the blood which passed through the 
divided vessels and the quills. The poison was then 
introduced under the skin of the foot, and soon occa- 
sioned the death of the animal: its deleterious effects 
commencing about four minutes after its application 
to the foot. This experiment appears to prove deci- 
dedly that the blood is the vehicle by which poison, 
when applied to the extremities, is carried to the body ; 
although it may not determine the question whether 
this poison was taken up by the absorbents or by the 
veins.* 

Some other experiments made by the authors gave re- 
sults, which are very difficult indeed to explain. They 
wished to know if the blood of an animal thus con- 
taminated, would produce similar effects upon another 
animal ; and, with a view to ascertain this point, they 
insinuated a small piece of wood, covered with the 
poison, into the thick part of the left side of the nose 
of a dog. Three minutes after the introduction of the 
poison, they transfused blood from the jugular vein of 
the same side, into one of the veins of another dog. 
About one minute after the commencement of the 



* This experiment has been repeated in Philadelphia. See Pro- 
fessor Chapman's Medical and Physical Journal for February 1823, 
No,10*~Ed. . ^ 



Beport of the Committee of the Institutes. 399 

transfusion, the effects of the poison began in the dog 
to which it was applied, and continued until his death. 
Transfusion into the veins of the other dog went on 
during the whole time, and he received a large quan- 
tity of blood from the dying dog, without producing 
any effect. — They varied this experiment in the fol- 
lowing manner. The thigh of a dog was separated 
from the body ; the artery and the vein were arranged 
as in the former experiment; and poison was intro- 
duced into the foot. Three minutes after the intro- 
duction of the poison, the blood of the crural vein was 
passed into the jugular vein of another animal, and 
transfusion was continued five minutes without pro- 
ducing any effect upon the animal receiving the blood ; 
it was then stopped, and the crural vein was so ar- 
ranged that the blood flowed from it into the animal 
to which it belonged. This animal very soon exhibited 
symptoms of the operation of the poison.* 

From these very interesting experiments the authors in- 
fer that *' foreign matters do not always proceed through 
the Lymphatic or Absorbent Vessels, when they enter 
into the Sanguiferous system.''^ 

This memoir was i*eferred by the Institute to four of its 
members, who are particularly distinguished by their 
profound knowledge of anatomy and physiology. These 
gentlemen, after stating their belief that the functions 
of the lymphatic or absorbent system have been com- 
pletely ascertained by the experiments and obser- 
vations of Hunter, Cruikshank, Mascagni, &c., say 
further, that, in their opinion, the above mentioned 
inference ought to be a little modified, and that facts 
are not sufficiently numerous, or applicable to the 
point in question, to justify the inference i\i^i foreign 
matters do not always proceed through the Lymphatic 
or Absorbent Vessels, when they enter the Sanguiferous 
system. But they also add, that, as the author is still 
engaged in a series of experiments on the subject, they 
will suspend their judgment respecting the inferences 
to be deduced from the present statement. 

* An account of these experiments was published by M. Magendie 
in a pamphlet. A statement of them is also contained in the report 
made to the Institute by the committee to whom the memoir was 
referred, which is published in the Journal de Physique, for March 
1813. In that statement this last mentioned experiment is omitted. 



400 Of the Absorbent System. 

The most extensive account of the absorbent system is 
contained in the " Historia et Ichnographia Vasorum 
Ljmphaticorum Corporis Humani" of Mascagni.— 
"The Anatomy of the Absorbing Vessels of the Human 
Body, by W. Cruikshank ;" — and " The Description of 
the Lymphatic System, by Wm.Hewson," (the second 
volume of his Experimental Inquiries) — are also very 
interesting publications. 



A most interesting series of inquiries and experiments in regard 
to the laws of absorption will be found in Professor Chapman's 
Journal of the Medical and Piiysical Sciences, No 6, in a report of 
a Committee of the Academy of Medicine, signed by Doctors Law- 
rence, Harlan, and Coates, of this city. — And a continuation of the 
same will be found in No. 10, of the sanne Journal, signed by Doc- 
tors Lawrence and Coates. Suice the publication of the latter, t© 
the regret of all who knew him, and to the great loss of Anatomy 
and of Physiology, the indefatigable and excellent Lawrence is no 
more. — Ed. 



APPENDIX. 



OF THE BLOOD. 

THE blood of a healthy person indicates a ten- 
dency to coagulate very soon after it is discharged 
from the vessels which naturally contain it, although 
it is perfectly fluid in those vessels. 

If it remain at rest, after it is drawn from the 
vessels, it soon coagulates into a solid mass, of a soft 
texture. From this solid mass a fluid is soon ob- 
served to issue, which first appears in very small 
drops on almost every part of the surface. These 
drops quickly increase and run together, and in a 
short time the fluid surrounds the solid mass, and 
exceeds it in quantity. 

The solid part which thus appears upon the 
spontaneous separation of the blood, is denominated 
Crassamentum or Cruor: the fluid part is called Se,- 
rum. 

The substance which contains the red colour of 
the blood remains with the Crassamentum. The 
Serum, when it separates without agitation, is free 
from the red colour. 

The colouring matter may be separated complete- 
ly from the Crassamentum by washing it with 
water. 

The blood, therefore, consists of three parts, viz. 
the Serum ; the Substance which coagulates spon- 
taneously ; and the Colouring Matter. 

Vol. II. 51 



402 Appendix.— Of the Blood, 

THE SERUM 

Has a considerable degree of consistence, although 
it is much thinner than blood. In its perfectly na- 
tural state, it is almost transparent, and appears to 
be very lightly tinged with a greenish yellow colour ; 
but it is very often impregnated with a portion of 
bile, which is probably carried to the blood vessels 
by the absorbents. It contains a large quantity of 
albumen, or matter like the white of an egg. If 
heated to 140° of Fahrenheit, it becomes opaque ; 
and when the heat is increased to 156 or 160, it is 
jBrmly coagulated. It is also coagulated by alcohol, 
by mineral acids, and by rennet.* It is proved by 
chemists, that it contains a small quantity of pure 
soda. It therefore changes several of the blue co- 
lours of vegetables green. It is also found to con- 
tain a similar quantity of the muriate and the phos- 
phate of soda, and the phosphate of lime. These 
saline substances were discovered by diluting serum 
with water, aud exposing the mixture to heat, by 
which the albumen was coagulated into flocculi : 
these flocculi were separated by iiltration : the li- 
quor was then diminished by evaporation, and the 
salts obtained from it by crystallization. 

Serum likewise contains a portion of sulphur com- 
bined with ammonia. 

When it is exposed to a coagulating heat, a small 
portion of it remains fluid. 

This fluid portion has been supposed to contain a 
considerable quantity of gelatine ; but it is contend- 
ed by Mr. Brande,t that Gelatine does not exist in 

* See Hewson, Vol. I. p. 139. — I suspect that some particular 
management is necessary in the use of rennet. 

t In hisResearches on the Blood communicated to the Royal So- 
ciety of London in 1812, and republished in the Eclectic Reper- 
tory, for April 1813. 



Appendix. — Of the Blood. 403 

the serum of the blood, and that this portion consists 
of albumen combined with a proportion of alkali. 

It is also asserted by Dr. Bostock,* one of the 
latest writers on the subject, that the serosity of the 
blood (the term applied to the last mentioned fluid) con- 
tains no gelatine ; but that, with a minute quantity 
of albumen, it consists of a large portion of an animal 
matter, which is different either from gelatine or al- 
bumen, being unlike either of them in its chemical 
qualities. 

THE CRASSAMEl^TUM 

Is rendered very different in its appearance, by the 
different circumstances in which it may coagulate. 

When the blood remains at rest immediately after 
it is drawn, the crassamentum which forms in it is a 
concrete substance, without the smallest appearance 
of fibre in its composition. If the blood is stirred 
with a rough stick, while it is flowing from an animal, 
a large portion of it will concrete upon the stick in a 
fibrous form, so as to resemble a mass of entangled 
thread, some of the red colouring matter still adhe- 
ring to it. 

The crassamentum, in either of these forms, may 
be washed perfectly white ; the red colouring matter 
passing completely away with the water. In this 
state it appearsf to have all the chemical properties 
of the fibrous matter of muscular flesh. It also re- 
seml)les the gluten of vegetables, being soft and elas- 
tic. The name fibkin is now generally applied to it. 

If FIBRIN is washed and dried, its weight is very- 
small indeed when compared with that of the blood 

♦ See his Observations on the Serum of the Blood, in the Medico- 
Cliinirgical Transactions, Vol. II, republislTied in the Eclectic Re- 
pertory, for October 1812. 

t By tlie experiments of Mr. Charles Hatchett, published in the 
Loudon I'hilosophical Transactions for 1800. 



404 appendix. — Of the Blood. 

from which it has been obtained. It is, therefore, 
probable that a considerable proportion of the bulk 
of the crassamentumj as it forms spontaneously, de- 
pends upon the serum which exists in it, and can be 
washed away. 

The spontaneous coagulation of the blood, which 
appears to depend principally upon the Fihrin, may 
be prevented by the addition of several foreign sub- 
stances to the blood, when it is drawn. It is subject 
to great variations that depend upon the state of the 
body at the time of bleeding ; and in some conditions, 
it does not take place at all.* 

In a majority of dead subjects the blood is found 
more or less coagulated in the veins ; but in some 
subjects it is found without coagulation. It is as- 
serted that it does not coagulate in subjects who have 
died suddenly, in consequence of anger, lightening, 
or a blow on the stomach. 

THE COLOURING MATTER. 

When the blood vessels in the transparent parts of 
certain living animals are examined with magnifying 
glasses, it appears that the red colour of the blood 
is owing to bodies of a globular form, which are dif- 
fused through a transparent fluid. The appearance 
of these bodies has been examined, with great atten- 
tion, by many physiologists, since the publication 
of Leuwenhoeck, in the London Philosophical 
Transactions.! 

* See an Inquiry into the Properties of the Blood, by the late Wm. 
Hewson : and Experiments by his son, T. T. Hewson, in the Eclec- 
tic Repertory, Jan. 1811. — See also a Treatise on the Blood, &c. by 
the late J. Hunter. 

f Among the most distinguished of these observers were Father 
de la Torre, Haller, Hewson, Fontana, Spalanzani, J. Hunter, Ca- 
vallo. 

Some short accounts of Leuwenhoeck's original observations on 
the blood are to be found in the Philosophical Transactions of Lon 



appendix. — Of the Blood. 405 

Several of these gentlemen have described the ap- 
pearance of the blood very differently ; bat Haller, 
Spalanzani and J. Hunter agree that the figure of 
the red particles is globular.* Hunter observes 
further, tliat the red globules do not run into each 
other as two globules of oil would do when divided 
by water ; and he believes that they cannot unite. — 
At the same time they seem not to have the proper- 
ties of a solid : for when circulating in the vessels, 
they assume elliptical forms, adapting themselves to 
the size of the vessels. They also excite no sensa- 
tion of solidity when touched. 

They appear to be more heavy than the other 
parts of the crassamentum : for in healthy blood the 
lower part of the mass contains more of the colour- 
ing matter than the upper part ; and in tlie blood of 
persons who labour under acute local inflammation, 
they often subside completely from the upper part; 
and thus occasion what is called, by Mr. Hewson, 
the inflammatory crust, or size. 

It has been observed by Mr. Hewson, and also 
by Mr. Hunter, that the globules do not retain their 
form in every fluid. They are said to be dissolved 

don, for 1664, in the fasciculi which are numbered 102 and 106. A 
more full description is contained in Boerhaave's Academical Lec- 
tures on the Theory of Physic. See the section on the nature of the 
blood. 

The t^lasces of Father de la Torre were transmitted from Naples 
to the Royal Society of London in 1765. They were accompanied 
by a letter from Sir F. H. E. Stiles, to which are subjoined some ob- 
servations by the Rev. Father himself. The letter and the observa- 
tions are published in the 55th volume of the Transactions of that so- 
ciety. 

In the year 1798, Tiberius Cavallo published an Essay on the 
Medicinal Properties of Factitious Air, with an appendix on the 
Nature of the Blood ; in which is contained a further account of the 
glasses of Dc la Torre. 

• I believe tiiat this is also the opinion of Fontana — In J. Hunter's 
work, on the Blood there are some interesting observations on micro- 
scopical deceptions. See the note, commencing in page 39, Brad- 
ford's edition . 



406 Appendix.'—Ofthe Blood. 

very quickly in water, and tlien they form a iine 
clear red. Several of the neutral salts, when dis- 
solved in water, prevent tlie solution of the globules. 
Mr. Hunter iiiforrus us, that the vitriolic acid, when 
greatly diluted, does not dissolve thera, &c. The 
muriatic acid, when three times as strong as vinegar, 
destroys their colour without dissolving them, al- 
though when more diluted, it dissolves them. 

The colour of the blood has, for a long time, been 
supposed to depend upon Iron. About the middle 
of the last century, Vincentius Menghini published 
in the Transactions of the Academy of Sciences of 
Sologna, an account of experiments which contri- 
buted to establish this sentiment. In this account 
he stated, that, after washing the colouring matter 
from the crassamentum, he had separated it from the 
water by boiling ; in which case it either rose to the 
surface of the water, or subsided, and left the water 
clear. After drying, with a gentle heat, some of 
the colouring matter thus separated, and then re- 
peatedly washing it, he found that it contained a 
considerable quantity of iron^ which was attracted 
hj the magnet. 

After exposing a large quantity of the colouring 
matter to an intense heat, he found in it a small 
piece of iron, of a spherical form, but hollow ; and 
a powder which was attracted by the magnet, but 
appeared more like rust of iron than iron filings. 

He believes the seat of this iron to be in the 
colouring matter of the blood, as neither the serum 
nor fihrine appeared to contain it. According to his 
calculation, the blood of a healthy man contains 
more than two ounces of iron. 

This doctrine of Menghini has been very gene- 
rally admitted ; and several chemists of the first 
character, viz. Bucquet, Fourcroy, Vauquelin, &c. 



Appendix,— Of the Blood. 407 

have made experimeuts to ascertain the substances 
with which the iron in the blood is combined. 

But within a few years, doubts have been ex- 
pressed on this subject by several physiologists, 
and especially by Dr. Wells, and Mr. Brande. 

The first of these gentlemen, in his *• Observations 
and Experiments on the Colour of the Blood,^^ pub- 
lished in the London Pliilosophical Transactions 
for 1797, states three reasons for rejecting the opi- 
nion that the colour of the blood is derived from 
iron. 

1. The colour of blood is destroyed by a heat 
less than that of boiling water ; whereas no colour 
arising from a metal is destroyed by exposing its 
subject, in a close vessel, to such a heat. 

2. If the colour from a metal, in any substance, be 
destroyed by any alkali, it may be restored by the 
immediate addition of an acid ; and the like will 
happen by the addition of a proper quantity of an 
alkali, if the colour has been destroyed by an acid. 
The colour of blood, on the contrary, when once 
destroyed, can never be brought back, either by an 
acid or an alkali. 

3. If iron be the cause of the red colour of blood, 
K must exist there in a saline state ; since the red 
matter is soluble in water. The substances, there- 
fore, which detect the smallest quantity of iron in 
such a state, ought likewise to demonstrate its pre- 
sence in blood ; but upon adding Prussian alkali, 
and an infusion of galls, to a very saturated solution 
of the red matter, he could not observe " in the former 
case the slightest blue precipitate ; or in the latter 
that the mixture had acquired the least blue or pur- 
pie tint." 

Mr. Brand e, in a paper entitled ^^ Chemical Re- 
searches on the Blood,^' &c. communicated to the 
Royal Society of London in 1812, relates many ex- 



408 Appendix. — Structure of the Glands. 

periments which were made on the colouring matter 
of that fluitlj with acids, alkalies, astringents, &c. &c. 
From these experiments, he also infers, that the co- 
louring matter of the blood is perfectly independent 
of iron. 

In support of this inference, he adds, that the Ar- 
menian dyers, in the preparation of their finest and 
most durable red colours, use blood in addition to 
madder, in order to insure the permanency of these 
colours. As the compounds of iron convert the. co- 
lour of madder to gray and black, the production of 
a bright colour, by the addition of blood to madder, 
he regards as a proof, that iron is not the colouring 
matter of blood. 

Many estimates have been made of the quantity 
of blood in the human body ; but some of the best in- 
formed physiologists have regarded them as falla- 
cious. 



STRUCTURE OF GLANDS. 

Any original structure that discharges from the 
blood vessels a fluid different from those which they 
naturally contain, may be considered as glandular. 
The function or process by which such fluids are- 
derived from the blood vessels is called sec?^etion. 

A structure of this kind seems to exist in very 
different situations : for it is distinctly circumscribed 
in many of those bodies commonly denominated 
glands, which are of a very precise form ; and it is 
also diffused on some very extensive surfaces. The 
gastric liquor, a most important secretion, is proba- 
bly discharged from vessels which open, like exha- 
lents, on the internal surface of the stomach ; and 
not from any circumscribed bodies, which are gene- 
rally denominated glands. 

Th^ name of gland is theoretically applied to 



Appendix. — Structure of Gla?ids. 409 

sevpral bodies which cannot be proved to secrete 
any fluid whatever; and also to those bodies con- 
nerted with the absorbent vessels, which are called 
the Lymphatic Glands ; but it is most commonly ap- 
propriated to those organs whicli discharge a fluid 
different from the blood. 

The structure by which mucus is secreted in some 
places, appears to be very simple. Thus in the 
Schneiderian membrane and the urethra, there are 
small ducts from four to six lines in length, and 
equal in diameter to a bristle, which appear to be 
formed of the membrane on which they open. From 
these ducts mucus issues to cover the surfaces of 
these membranes. In many instances there is no 
substance resembling that of the circumscribed gland- 
ular bodies, connected with these ducts ; but the 
secreted fluid seems to be discharged into the ducts 
from the small vessels on their surfaces. The ducts 
of this nature in the urethra are denominated La- 
cunse. 

In some other parts of the body, the cavities into 
which mucus is discharged are somewhat different, 
both in form and size, from those above mentioned, 
and are called Follicles. These cavities are sur- 
rounded with more or less of a pulpy vascular sub- 
stance, which has been considered as glandular, and 
essential to the mucous secretion. 

The circumscribed bodies, which are commonly 
called glands, differ in their internal appearance and 
texture, from the other parts of animals. The sub- 
stance of which they consist differs very much in 
the different glands ; and thus renders the liver, kid- 
neys, salivary glands, mainmse, &c. very different 
from each other. Some glands, as the salivary, &c. 
are composed of several series of lobuli that suc- 
cessively diminish. The smallest of these are de- 
nominated Acini. Each of them is connected by a 

Vol. II. 52 



410 dppendix. — Structure of Glands. 

small artery and vein, to the large blood vessels of 
the glands ; and also sends a branch to join the ex- 
cretory duct. These Acini are therefore connected 
to each other, by the blood vessels and excretory 
duct of the gland, and also by the cellular membrane, 
which covers them externally, and occasions them 
to adhere to each other where they are in contact. 
In consequence of this structure, these glands have 
a granulated appearance. 

The liver, when incised with a sharp instrument, 
appears differently; but when broken into pieces, it 
seems to consist of small acini. Some other glands, 
as i\\Q^^ Prostate, appear to be uniform in their texture, 
and have none of this granulated appearance. 

The structure of glands has long been an interest- 
ing object of anatomical inquiry, and was investiga- 
ted with great assiduity by those eminent anatomists, 
Malpighi and Ruysch. 

Malpighi, as was formerly observed, used ink and 
other coloured fluids in his injections. He was also 
very skilful in the use of microscopes, and took great 
pains in macerating and preparing the subjects of his 
inquiries. Ruysch, on the other hand, used a ce- 
raceous injection, and was most eminently successful 
in filling very small vessels with it. Malpighi be- 
lieved that there were follicles or cavities in glandu- 
lar bodies, which existed between the extremities of 
the arteries and the commencement of the excretory 
iucts of those bodies, and that in these cavities the 
secreted fluids underwent a change. — Kuysch con- 
tended, that the arteries of glands were continued 
into execretory ducts without the intervention of any 
cavity or follicle ; that the small bodies, which had 
been supposed to contain follicles or cripse, were 
formed by convulsions of vessels, and that the change 
of the fluid, or the process of secretion, is produced 
by the minute ramifications of the artery. 



Appendix. — Structure o^ Glands. 411 

A very iuteresting account of this subject is con- 
tained in two celebrated letters, which passed be- 
tween Boerhaave and Ruysch in the year 1721, .and 
are published at the end of the fourth volume of the 
works of Ruysch. 

The opinion of Ruysch has been most generally 
adopted by anatomists, and has derived support and 
confirmation from several anatomists since his time. — 
The late Mr. Hewson declared his conviction that 
the small globular bodies which are scattered through 
the kidneys, and were supposed to be follicles or 
criptse, are merely convoluted arteries. He also as- 
serted, that the acini w hich appeared in the mammse. 
as large as the heads of pins, when the excretory 
ducts of that gland were injected with vermilion and 
painters' size, proved to be the minute ramifications 
of the excretory duct, which divided very suddenly 
into branches so small, that they could not readily 
be seen by the naked eye.* 

Notwithstanding these reasons for supposing that 
the excretory ducts of glands were derived simply 
from the arteries of those bodies, it is said that the 
late Dr. W. Hunter used to declare his belief, that 
there was a part in glands which was not injected, 
in his preparations ; and to say further, that he be- 
lieved his preparations were injected as minutely as 
those of Ruysch. 

All of these opinions have been strenuously con- 
troverted by the Italian anatomist, Mascagni, who 
believes that the arteries terminate only in veins ; 
and of course that they neither form exhalent ves- 
sels, nor communicate with the excretory ducts of 
glands. His idea of the structure of glands is dif- 
ferent from those either of Malpighi or of Ruysch. 
He supposes that glands contain a great number of 

• See Experimental Inquiries, vol. ii. p. 17R 



412 Appendix. — Structure of Glands. 

minute cells ; that the arteries, veins, and absorbent 
vessels are spread upon the surfaces of these cells, 
in great numbers, and very irregularly. From these 
cells very small canals originate, which unite to ^ 
form the small branches of the excretory ducts. — 
According to his idea, the secreted fluid is dis- 
charged through pores or orifices of the blood ves- 
sels, into the cells, and proceeds from them, through 
the canals, into the branches of the excretory ducts. 
Absorbent vessels, in great numbers, originate from 
these cells. 

In his great work on the absorbent system, when 
treating on the termination of arteries and the com- 
mencement of veins, (Part I. Section 2.) he asserts, 
that if the kidneys are successfully injected with 
size, coloured with vermilion, and then laid open by 
a section with a razor, it will be found that the size 
without the colour has passed into cells, which are 
very numerous ; that the arteries and veins are ra- 
mified most minutely on the surfaces of these cells, 
and that the tubuli uriniferi, as well as the absorbent 
vessels, originate from them. 

He supposes that a considerable portion of the 
fluid thus passing off from the blood vessels, is com- 
monly taken up by the absorbent vessels of the kid- 
neys ; for in two cases in which he found the ab- 
sorbent vessels obstructed, a diabetes existed, which 
he considered as the effect of the inactivity of the ab- 
sorbents. He asserts, that in the liver, pancreas, 
mammse, and also in the salivary and lachrymal 
glands, the minute arteries and veins are also distri- 
buted upon the surfaces of cells ; and that very small 
canals arise from these cells, and unite to form the 
small branches of the excretory ducts. 

This great anatomist appears to have been much 



Appendix. — Structure of Glands. 413 

occupied with microscopical observations, and has 
gone largely into the discussion of this subject.* 

It must, however, be acknowledged, that no information 
which has as yet been obtained respecting the struc- 

. ture of glands, enables us to explain their wonderful 
effect upon the fluids which pass through them. It re- 
mains yet to be ascertained why one structure forms 
saliva and another bile ; or why so much apparatus 
should be necessary for the secretion 'of milk, when 
adipose matter appears to be produced by the mere 
membrane in which it is contained. 

Dr. Berzelius, professor of Chemistry at Stockholm, iii 
a late work on animal chemistry, asserts, tliat if all 
the nerves going to a secretory organ are divided, se- 
cretion will cease, notwithstanding the continued cir- 
culation of the blood. From this, he thinks, that se- 
cretions depend upon the influence of nerves, although 
he cannot explain their effects. 

Mr. Home, after relating some experiments upon blood 
and serum, made with the Voltaic Battery, proposes 
the following questions, among others : Whether a 
weaker power of electricity than any which can be 
kept up by art, may be capable of separating from the 
blood the different parts of which it is composed; and 
forming new combinations of the parts so separated ? 
—Whether the structure of the nerves may enable 
them to possess a low electrical power, which can be 
employed for that purpose ? &c. 

See the London Philosophical Transactions, for 
1809, Part Il.t 

* The late Dr. W. Hunter, in his Medical Commentaries, (p. 40,) 
avowed his belief, that the fluids, which appear occasionally in the 
various cavities of the body, transude through the coats of the blood 
vessels. Mr. Hewson (Experimental Inquiries, Vol. II. Chap T".) 
suggested several reasons for dissenting from this opinion ; but 
Mascagni has endeavoured to support it.— See a long nots to the 
above mentioned section of his work, page 74. 

t Mr. Wollaston has also published a small paper on this subject 
in the P^hilosophical Magazine, Vol. 3i^. 



GLOSSARY,* 



EXHIBITING THE DERIVATION OF CERTxVIN ANATOMICAL 
TERMS, 



A. 



ACETABULUM. The cavity which receives the head of the 
thigh-bone; from acetiim vinegar: so called, because it re- 
presents the acetabulum or saucer of the ancients, in which 
vinegar was held for the use of the table. 

Aciyii. From acinus a grape. 

Acromion. A process of the scapula; from «xpoj extremity, 
and uixot the shoulder. 

Anastomosis. The communication of vessels with one ano- 
ther; from ana. through, and s-o/x« mouth. 

Anatomy. The dissection of the human body; from ava, and 
TtAtvo to dissect. 

Anconeus. A muscle ; so called from ayx-m the elbow. 

Aorta. AopT« from ; ««g air, and Ttigiu to keep. 

Aponeurosis. A tendinous expansion ; from a^ro, and v«t/pov a 
nerve ; from an erroneous supposition of the ancients, that 
it was formed by an expansion of nerve. 

Apophysis. A process of a bone ; from «!Ta<pu» to proceed 
from. A synonyme of process. 

Arachnoides. A net-like membrane ; from apa;^'''' ^ spider, and 
j/ifos likeness. 

Artery. From ««§ air, and rnosa to keep ; because the ancients 
supposed that air only was contained in them. 

Arthrodia. A species of connexion of bones ; from apdpoo) to 
articulate. 

Aryfsenoides. The name of two cartilages of the larynx; also 
applied to some muscles of the larynx ; from etfuraiva a fun 
nel, and uJ'oi a shape. 

* By Ur. Hooper. 



416 Glossary. 

.Astragalus. A bone of the tarsus; so called from its resem- 
blance to a die used in ancient games, from ttsf»ya\tt a 
cockal or die. 

Atlas. The first vertebra of the neck; so called, because it 
sustains the head : from the fable of Atlas being supposed 
to have supported the world ; or from «TXa<» to sustain, be- 
cause it sustains the head. 

dzygos. A term applied to parts without a fellow,^from « priv. 
and tyyti a yoke, because it has no fellow. 

B. 

Bursa. A bag; from ySupira: generally applied to the bursse 
muscosse. 

C. 

Cancelli. Lattice work; generally applied to the reticular 

substance in bones. 
Cardia. The superior opening of the stomach ; from Knf^itt the 

heart. 
Carotid. The name of some arteries of the neck and head from 

Kttfou to cause to sleep ; for, if tied with a ligature, the ani- 
mal was said to be affected with coma. 
Carpus. Kaivcg; the wrist. 
Clavicula. The clavicle or collar-bone, a diminutive of clavis 

a key; so called from its resemblance to an ancient key. 
Clinoid. Four processes of the sella turcica of the ethmoid bone 

are so called, from ^xm a bed, and w/oc likeness ; from their 

supposed resemblance to a couch. 
Clitoris. A part of the female pudenda, enclosed by the labia ' 

majora; from icxuuio enclose or hide. 
Colon. The first of the large intestines; from itaxov, quasi xoixov. 

from )i6/xo{ hollow. 
Coracoid. From xog«^ a crow, and uiftg resemblance; shaped 

like the beak of a crow. 
Coronary. From corona a crown. The vessels of the heart, 

stomach, &c. are so called because they surround the parts 

in the manner of a crown. 
Cotyloid. From *«tuAj) the name of an old measure, and «/ofre- 

s.emblance ; resembling the kotule. 
Cranium. The skull ; »p«y<Bv, quasi Kafmtov, from ««p« the head. 
Cremaster. A muscle so called ; from jsgiftaw to suspend, be- 
cause it suspends the testicle. 
Cribriform. From cribrum a sieve, it being perforated like a 

sieve. 



Glossary. 417 

Cricoid. Annular, round like a ring; from Kgi)t»s a ring, and 

itjoj likeness. 
Cuboides. A bone of the foot; from »ti/Coc a cube, and ii<f'<^i 

likeness; because it resembles a cube. 
Cuneiform. Some bones are so called ; from cimeus a wedge, 

a,nd forma likeness; being shaped like a wedge. 

D. 

Deltoid. A muscle resembling the Greek letter a ; from a, 
and ucTos resemblance. 

Diaphragm. The muscle which separates the thorax from 
the abdomen; from ifixf^ctrlu to divide. 

Diarthrosis. A moveable connexion of bones ; from i't»^6^oa to 
articulate. 

Digastric. From //c twice, and yttsti^ a belly ; having two bel- 
lies. 

Diploe. The spongy substance between the two tables of the 
skull; from J'ltnrMa to double. 

Duodenum. The first portion of the small intestines ; so called 
because the ancients supposed that it did not exceed the 
breadth of twelve fingers; from duodenus, consisting of 
twelve. 

Dura Mater. The outermost membrane of the brain ; called 
dura, because it is much harder than the other membranes, 
and mater, from the idea of the ancients that it was the 
source of all the other membranes. 

E. 

Embryo. The child in the womb is so called before the fifth 
month, after which it is termed foetus; from tfufipvu to bud 
forth. 

Enarthrosis. An articulation of bones ; from a in, and a^^^n a 
joint or articulation. 

Enteric. Belonging to the intestines; from «i»t«jot an entrail or 
intestine. 

Epidermis. The scarf or outermost skin ; from ««■/ upon, and 
S'i^fAii the skin. 

Epididymis. The small oblong body which lies above the tes- 
ticles; from ETTi upon, and J'Kf'ufttf a testicle. 

Epigastric. The superior part of the abdomen; from t7r/ upon, 
and >«5T«g the stomach. 

Efiiglotlis. A cartilage of the larynx so called ; from uti upon, 
and yx«T]<c the aperture of the lai-ynx, being situated upon 
the glottis. 

Epiphysis. A portion of bone growing upon another bone, but 
Vol. II. 53 



4lS Glossary, 

separated from it by a cartilage : from %-jrt upon, and <?>«/« to 
grow. 

Epiploon. The membranous viscus of the abdomen, which co- 
vers the intestines, and hangs to the bottom of the stomach; 
from fjriTfKiU) to swim upon. 

Ethmoid. From i9^oc a sieve, and «/o{ resemblance; being per- 
forated like a sieve. 

F. 
Fascia. An expansion, enclosing other parts, like a band ; from 

fascis a bundle. 
Falciform. Shaped like a sithe; homfalx, a sithe. 
Fasciculus. A little bundle, dim. of fascis a bundle. 
Fauces. The plural of faux, the top of the throat. 

G. 

Ganglion. Fnfyxnv, a knot in the course of a nerve. 

Gastrocnemius. The muscle which forms the thick of the leg; 
from >a5J»g a belly, and kv«^i» the leg. 

Genio. Names compounded with this word belong to muscles 
which are attached to the chin, as genio-glossus — genio- 
hyoideus, &c.; from >tvs/ov the chin. 

Ginglymus. An articulation ; from ^/f^xfjttoc a hinge. 

Glenoid cavity. From yxnm a cavity, and mPo^ resemblance. 

Glosso. Names compounded with this word belong to muscles 
which are attached to the tongue ; as glosso-pharyngeus — 
glosso-staphilinus, &c.; from yxaxnTu. the tongue."? 

Glottis. The superior opening of the larynx at the bottom of 
the tongue: from y-Ku'tlu the tongue. 

Glutaeus. The name of a muscle; from ^x^toc the buttocks. 

Gomphosis. T»[x<^uffn, a species of immoveable connexion of 
bones ; from yr,^<^Qt a nail, because one bone is fixed in ano- 
ther bone like a nail in a board. 

H. 

Helix. The outward circle of the ear; from hmc* to turn about. 

Hepar. The liver. "Hjrtfj an abdominal viscus. 

Hyaloid. From CuXot glass, and t<3oc likeness; the capsule of 
the vitreous humour of the eye is so called, from its trans- 
parent and glassy appearance. 

Hymen. The membrane situated at the entrance of the virgin 
vagina; from 'Y/^mv Hymen, the god of marriage. 

Hyoides. A bone of the tongue, so called from its resemblance 
to the Greek v; from u, and t//o? resemblance. 



Glossary, 419 

Hypochondrium. That part of the body which lies under the 
cartilages of the spurious ribs; from vtto under, and ;govi/'goc 
a cartilage. 

Hypogastric. The lower region of the fore part of the abdo- 
men; from «/V» under, and yac»g the stomach. 

I. 

Ileon. A portion of the small intestines ; from uXtu to turn ; 

being always convoluted. 
Ischium. The part of the os innominatum upon which we sit; 

from icy^vu to sustain. 

L. 

Lacuna. The excretory duct of the glands of the urethra and 
vagina ; from lacus a channel. 

Lambdoidal suture. So called because it is shaped like the let- 
ter X ; from \, and n^o? resemblance. 

Larynx. The superior part of the windpipe ; ha^vy^ the larynx. 

M. 

Massefer. A muscle of the face, which assists in the action of 
chewing; |6*a3-ff^ao^«/ to chew. 

Mastoid. From ftayoj a breast, and £«fo{ likeness ; shaped like 
a nipple or breast. 

Mediastinum. The production of the pleura, which divides the 
thorax into two cavities; from medium the middle, quasi in 
medio stare. 

Mesentery. The membranes to which the intestines are at- 
tached ; from fAKrof the middle, and «»Tf(;o» an intestine, be- 
cause it is in the middle of the intestines. 

Mesocolon. That part of the mesentery in the middle of th« 
colon ; from /ut«-o? the middle, and itsxov the colon. 

Metacarpus. That part of the hand between the carpus and fin- 
gers ; from /ust* after, and urt^To? the wrist. 

Metatarsus. That part of the foot between the tarsus and toes ; 
from ftfrx after, and Ta^o-o; the tarsus. 

Mylo. Names compounded with this word belong to muscles 
which are attached near the grinders, as mylo-hyoideus, &C.5 
from fjLvXri a grinder tooth. 

O. 

Odontoid. Tooth-like; from oj»catooth, and i//»e resemblance. 

(Esophagus. The canal leading from the pharynx to the sto- 
mach ; from o/« to carry, and <^*yto to eat; because it carries 
the food into the stomach. 



420 Glossary. 

Olecranon. The elbow, or head of the ulna ; from oXijiq the cu- 
bit, and xga»o» the head. 

Omentum. An abdominal viscus ; so called from omen a guess ; 
because the soothsayers prophesied from the inspection of 
this part. 

Omo. Names compounded with this word belong to muscles 
which are attached to the scapula, as omo-hyoideus, &c., 
from «/;tec the shoulder. 

Omoplata. The scapula or shoulder blade ; from «/>to5 the shoul- 
der, and irx«Twc broad. 

Osteology. The doctrine of the bones; from osio» a bone, and 
Ao>«s a discourse. 

P. 

Pancreas. A viscus of the abdomen ; so called from its fleshy 
consistence ; from •7r«v all, and xgssf? flesh. 

Parenchyma. The substance of sume of the viscera was so 
called, from 5rag«>«t/« to pour through. 

Parotid Gland; from w«g« near, and oy? the ear; because it is 
situated near the ear. 

Pelvis. A bony cavity shaped like a basin ; from vtwt a basin. 

Pericardium. The membrane which surrounds the heart ; from 
vt^i around, and xttpi'i* the heart. 

Pericranium. The membrane which covers the bones of the 
skull ; from vi^i ai'ound, and «.^*noi the cranium or head. 

Periosteum. The membrane whi<jh surrounds the bones ; from 
Tsg/ around, and oyiev a bone. 

Peristaltic motion of the intestines ; from ai^nswu, to contract. 

Peritoneum. The membrane lining the abdomen, and cover- 
ing its viscera; from TCi^iitivu to extend around. 

Phalanx. The bones of the fingers and toes are called pha- 
lanxes, from their regular situation, like a fctxay^, or ar- 
rangement of soldiers. 

Pharynx. A membranous bag at the end of the mouth ; «n-o rs 
(pi^s/f, because it conveys the food into the stomach. 

Phrenic or diaphragmatic nerve. ^gtv»? the diaphragm ; from 
<pjij» the mind ; because the ancients supposed it to be the 
seat of the mind. 

Pia Mater. The innermost membrane of the brain, so called 
because it embraces the brain as a careful mother folds her 
child. 

Pleura. The membrane lining the thorax ; nuv^it the side. 

Plexus. A kind of net-work of vessels or nerves ; from plecto 
to weave together. 



Glossary. 421 

Psoas. A muscle so called ; from 40a the loin, being situated 
in the loins. 

Pterygoid process. From ^1«gi/^ a pen or wing, and t/cTej like- 
ness ; so called from its likeness to a pen or wing. 

Pylorus. The lower orifice of the stomach, which opens into 
the intestines ; from wxaa) to guard an entrance, because it 
guards as it were the entrance of the bowels. 

R. 

Raphe. A suture; from ^cnrlu to sew. 

Renes. The kidneys, ctTro ts ftu, because through them the 
urine flows. 

Retina. The net-like expansion of the optic nerve, on the 
inner surface of the eye; from rete a net. 

Rhomboides. A muscle so called from its shape ; from po^tiSBc 
a geometrical figure, whose sides are equal but not right- 
angled, and si<fot a likeness. 

Roiida. The knee-pan ; a dim. of rota a wheel, from its shape. 

S. 

Sacrum. A bone so called ; from sacer sacred, because it was 
once offered in sacrifices. 

Salvatella. A vein of the foot, so called because it was thought 
that opening it preserved health, and cured melancholy ; 
from salvo to preserve. 

Sanguis. The blood ; «i»-6 tb emn yu/<«, because it preserves the 
body. 

Sartorius. A muscle so called, because tailors cross their legs 
with it ; from sartor a tailor. 

Scapha. The depression of the outer ear before the anti-helix; 
from a)ct<fn a little boat or skiff. 

Scaphoides. A bone of the carpus, so called from its resem- 
blance to a skiff; from irxa'^n a skiff, and £/<fo? likeness. 

Sclerotic. A term applied to the outermost or hardest mem- 
brane of the eye; from <rx\>)go«to make hard. 

Sesamoid bones. From a-»<rttfiv a grain, and !//« likeness; from 
their resemblance to the semen sesami. 

Sigmoid. Parts are so called from their resemblance to the 
letter s ; from S, the letter Sigma, and «</oc likeness. 

Sphenoid. From «r<}.«v a wedge, and ti<fo; likeness; shaped like 
a wedge. 

Sphincter. The name of several muscles whose oflice is to 
shut up the aperture around which they are placed; from 

o-cpiyyu to shut Up. 

Splanchnic. From aTKetyx^ci, an entrail. 



422 Glossary. 

Symphysis. A connexion of bones; from cvfi^ua to grow to- 
gether. 

Synarthrosis. A connexion of bones; from (rw with, and «p9^o» 
a joint. 

Synchondrosis. A species of union of bones by means of car- 
tilage; from c-i/v with, and x°^^f''s ^ cartilage. 

Synneurosis. A species of connexion of bones by means of 
membrane ; from e-ov with, and veypoja nerve ; because mem- 
branes, ligaments, and tendons, were by the ancients con- 
sidered as nerves. 

Syssarcosis. A species of connexion of bones by means of 
muscle ; from a-n with, and o-a^^ flesh. 

Systole. The contractile motion of the heart and arteries; 
from o-j/s-Tsxxa to contract. 

T. 

Tendon. From TBiia to extend. 

Thorax. Gagaf. The breast or chest. 

Thyroid. From Ougm a shield, and «//oj likeness; shaped like 
a shield. 

Trachea. The windpipe, so called from its roughness ; from 
T^ttx^i rough. 

Trochanter. A process of the thigh-bone, so called from r^i^^i 
a wheel. 

U. » 

Ulna. A name for the cubit ; from &?.«» the cubit. 

Ureter. The canal which conveys the urine from the kidney 
to the bladder; from s^ov urine. 

Urethra. The passage through which the urine passes from 
the bladder; from kjov the urine. 

Uvea. The posterior lamina of the iris, so called because in 
many animals it is of the colour of unripe grapes; from 
uva an unripe grape. 

Uvula. The conical substance which hangs down from the mid- 
dle of the soft palate : so called from its resemblance to a 
grape. A dim. of uva a grape. 

V. 

Valves. From vulvae folding doors. 

Verfebrse. The bones of the spine are so called ; from verto to 
turn. 

X. 

Xiphoid. So called from the resemblance to a sword ; from 
ft^os a sword, and i/cfo? likeness. 

Z. 

Zygoma. The cavity under the zygomatic process of the tem- 
poral bones ; from ^vytg a yoke. 




ALPHABETICAL INDEX TO VOLUME IL 





Page 


Aorta 50 & 236 


Adhesion of lungs 


73 


Abdomen 


82 


regions of 


86 


contents of 


85 


situation of vis 


* 


cera 


87 


Acini of liver 


132 


Arteries, structure of 


226 


Arterj, axillary 


262 


aorta thoracic 


270 


abdominal 


274 


adipose 


281 


anastomotic 


292 


anterior tibial 


294 


basilic 


259 


bronchial 


270 


carotid 


239 


external 


240 


internal 


250 


callous 


256 


cervical 


261 


circumflex 


564 


cceliac 


275 


capsular 


280 


circumflex of ili- 




um 


289 


ofthig 


ti291 


emulgent 


280 


epigastric 


288 


facial 


242 


femoral 


289 


gastric 


275 


right 


276 


left 


277 


gluteal 


286 


lumeral 


264 


hepatic 


276 


hsemorrhoidal 


285 


innominata 


238 


VOL. II. 


A 



Page 
Artery, internal maxillary245 
mammary257 
intercostals supe- 
rior 260 
interosseal 267 
intercostals infe- 
rior 272 
iliac primitive 282 
internal 283 
ilio lumbar 284 
iliac external 288 
internal plantar 296 
ischiatic 286 
lingual 242 
lumbar 282 
middle of brain 255 
mammary exter- 
nal 262 
mesenteric supe 
rior 278 

infe- 
rior 279 

occi- 
pital 244 
ophthalmic 252 
cesophageal 271 
• obturator 285 
pharyngeal infe- 
rior 243 
phrenic 274 
pudic internal 287 
external 290 
profunda femoris ~90 
perforating 291 
popliteal 292 
posterior tibial 295 
peroneal ib. 
plantar external 296 
radial 266 
stylo-mastoid 245 



11 



INDEX. 



Artery, subclavian 256 

scapular superior 260 

internal 263 

spiral 265 

splenic 277 

spermatic 281 

sacral middle 28- 

lateral 284 

thyroid sujierior 241 

inferior 258 

temporal 24P 

ulnar 268 

• uterine 286 

vertebral 258 

Arterial system, plan of 297 
Abdominal viscera, nerves 

of 368 

Absorbents, structure of 371 
of lower ex- 
tremity 376 
of abdomen S8l 
of thorax 389 
of head and 

neck 391 

of upper ex- 
tremity 393 
Absorption, cutaneous 395 

Black glands 64 

Bile . 141 

Bladder of female 213 

Blood vessels in general 223 
Blood * 401 

colouring matter of 404 

Cavities of nose 4 

C cecum 118 

Colon _ 119 
Corpus pampini forme 174 

Corpora cavernosa 186 

Corpus spongiosum 188 

Canal of urethra 190 

Clitoris ^ 201 

Canalis arteriosus 220 

Cavse ^ 299 

Coronary veins Jb* 



Chorda Tympani 


335 


Crassamentum 


403 


Duodenum 


111 


Ductus communis 


141 


Dartos 


173 


Ductus venosus 


220 


Descending cava 


300 


External nose 


S 


Eustachian tube 


11 


Epididymis 


177 


Fauces 


28 


Foetus, thorax of 


69 


heart of 


ib. 


lungs of 


ib. 


abdomen of 


217 



Female organs of genera- 
tion 200 
Fallopian tubes 209 



Gums 


16 


Glandulse molares 


26 


Glottis 


34 


Gastric liquor 


101 


Great intestines 


117 


Gall bladder and duct 


139 


Glandulse renales 


154 


Ganglions 


321 


of Gasser 


327 


sphino palatine 329 


cervical 


361 


semilunar 


367 


Glands, structure of 


408 


Glossary 


415 


Heart 


50 


malformations of 


72 


nerves of 


363 


Hepatic duct 


13» 


Hymen 


202 


Hottentots, peculiarity of 216 


Intestines 


104 



villous coat of 105 
division of 109 





INDEX. 




111 


Intestines, small 


110 


Nerves, lumbar 


353 


Integuments of penis 


195 




laryngeal superior 


339 


Ilium 


113 




maxillai-y inferior 


332 








superior 3i9 


Jejunum 


113 




musculo cutane- 
ous 


348 


Kidneys 


155 




median 
ninth pair 


ib. 

342 


Larynx 


31 




olfactory 6. 


323 


arteries and nerves 




optic 


324 


of 


35 




opthalmic 


327 


Left auricle 


55 




obturator 


555 


ventricle 


56 




par vagum 


338 


Lungs 


65 




recurrent 


339 


Legallois on heart 


79 




radial 


350 


Liver 


128 




sixth pair 


335 


ligaments of 


ISO 




seventh pair 


334 


Labia externa 


201 




sacral 


356 


Lacteals 


38.) 




sciatic 


358 


Mouth 


14 




sympathetic 


361 


Mainmse 


41 




splanchnic 


367 


Mediastinum 


46 




third pair 


325 


Muscular fibres of heart 


57 




tibial posterior 


360 


Mesentery 


115 




ulnar 


349 


Male organs of generation 171 












(Esoph 


agus 


94 


Nose 


1 


Omentum 


125 


nerves of 


8 


Orifice 


of urethra 


167 


Nerves of liver 


136 


Ovaries 


210 


Neck of the bladder 


167 








Nerves, structure of 


319 


Parotid 


gland 


25 


accessory 


347 


Pharynx 


57 


of arm 


348 


Pleurse 




45 


of brain 


323 


Pericar 


dium 


49 


cervical 


343 


Pulmonary arteries and 




circumflex 


351 


veins 


61 


crural 


355 


Peritor 


leum 


90 


cardiac 


363 


Pylorus 


102 


of diaphragm 


246 


Pancreas 


141 


dorsal 


352 


Prostate gland 


183 


eighth pair 


336 


Penis 




184 


fourth pair 


325 


Prepuce 


196 


fifth pair 


3 -'6 


Placen 


ta 


221 


fibular 


359 


Plexuses 


321 


glosso-pharyngea 


337 




pulmonary 


340 


internal cutaneous 35 1 




brachial 


347 



lNDE3i. 



Plexuses lumbar 354 

cardiac 366 

solar 36r 

Rima glottidis 34 

Right auricle 52 

ventricle 53 

Rectum 122 

Round ligaments 209 

Schneiderian membrane 5 
Sinuses of nose 12 
Soft palate 17 
Salivary glands 25 
Submaxillary gland 26 
Sublingual gland ib. 
Saliva ib. 
Sabatier on foetal circula- 
tion 75 
Stomach 96 
lymphatics and 
nerves of 103 
Spleen 145 
Scrotum 171 
Serum 
Spermatic cord 173 

Tongue 18 

papillee of 20 

blood vessels of 23 

nerves of 24 

Throat 28 

Tonsils 29 

Thyroid gland 37 

Thorax 41 

Trachea 62 

Thymus gland 69 

Tunica vaginalis 175 

albuginea 176 

Testicle 177 

descent of 218 

Thoracic duct 387 



Uvula 


17 


Urinary organs 


154 


Ureters 


160 


Urinarv bladder 


162 



Urethra of male 188 
of female 202 
Uterus 205 
changes of, in preg- 
nancy 214 
Umbilical arteries 219 

Vense cavse 61 

Valve of colon 120 

Vena Portarum 134 

Vessels of liver 133 

Vas deferens 180 

Vesiculse seminales 181 

Vagina 203 

Veins, structure of 233 

distribution of 298 

Vena azygos 301 

Veins, axillary 308 

anomalies of 317 

basilic 308 

cephalic 308 

Cava inferior 309 

capsular 312 

circumflex 314 

external jugular 306 

emulgent 312 

external iliac 314 

epigastric 315 

external saphena 316 

femoral 315 

hepatic 311 

hypogastric 313 

intercostal superior 303 

iliac primitive 313 

jugular internal 304 

lumbar 313 

middle sacral ib. 

mesenteric superior 311 

phrenic inferior 310 

Vena portarum 311 

Veins pulmonary 317 

subclavian 307 

splenic 311 

spermatic 312 

saphena major 315 

vertebral 304 

vesical 315 



ANATOMICAL PLATES. 



EXPLANATION OF THE PLATES OF OSTEOLOGY, 



Plate XIX. 

Fig. 1. A Front-view of the Male Skeleton. 

A, The OS frontis. B, The os parietale. C, The Coronal 
suture. D, The squamous part of the temporal bones. E, The 
squamous suture. F, The zygoma. G, The mastoid pi'ocess. 
H, The temporal process of the sphenoid bone. I, The orbit. 
K, The OS malee. L, The os maxillare superius. M, Its nasal 
process. N, the ossa nasi. O, The os unguis, P, The maxilla 
inferior. Q, the teeth, which are sixteen in number in each 
jaw. R, The seven cervical vertebrae, with their intermediate 
cartilages. S, Their Transverse processes. T, The twelve 
dorsal vertebree, with their intermediate cartilages. U, The 
five lumbar vertebrse. V, Their transverse process. W, The 
upper part of the os sacrum. X, Its lateral parts. The holes 
seen on its fore part are the passages of the undermost spinal 
nerves and small vessels. Opposite to the holes, the marks of 
the original divisions of the bones are seen. Y, The os ilium. 
Z, Its crest or spine, a, The anterior spinous processes, b. The 
brim of the pelvis, c, The ischiatic niche, d, The os ischium, 
e, Its tuberosity, f. Its spinous process, g, Its crus. h, The 
foramen thyroideum. i, The os pubis, k. The symphysis pubis. 
1, The crus pubis, m. The acetabulum, n, The seventh or last 
true rib. o, The twelfth or last false rib. p, The upper end of 
the sternum, q, The middle piece, r, The under end, or car- 
tilage ensiformis. s. The clavicle, t, The internal surface of 
the scapula, u, Its acromion, v, Its coracoid process, w, Its 
cervix, x, The glenoid cavity, y, The os humeri, z, Its head 
which is connected to the glenoid cavity. 1, Its internal tu- 

A 



2 Explanation of the Plates of Osteology. 

bercle. 2, Its internal tubercle. 3, The groove for lodging the 
long head of the biceps muscle of the arm. 4, The internal 
condyle. Between 4 and 5, the trochlea. 6, The radius. 7, Its 
head. 8, Its tubercle. 9, The ulna. 10, Its coronoid process. 
11, 12, 13, 14, 15, 16, 17, 18, The carpus; composed of os 
naviculare, os lunare, os cuneiform, os pisi forme, os trapez,i- 
um, OS trapezoides, os magnum, os unciforme. 19, The five 
bones of the metacarpus. 20, The two bones of the thumb. 
21, The three bones of each of the fingers. 22, The os femoris. 
23, Its head 24, Its cervix. 25, The trochanter major. 26, 
trochanter minor. 27, The internal condyle. 28, The external 
condyle. 29, The rotula. 30, The tibia, 31, Its head. 32, Its 
tubercle. 33, Its spine. 34, The malleolus internus. So, The 
fibula. 36, Its head. 37, The malleolus esternus. The tarsus is 
composed of. 38, The astragalus ; 39, the os calcis ; 40, The 
OS naviculare ; 41, Three ossa, cuneiformia, and the os cu- 
boides, which is not seen in this figure. 42, The five bones of 
the metatarsus. 43, The two bones of the great toe. 44, The 
three bones of each of the small toes. 

Fig. 2. A Front-view of the Skull. 
A, The OS frontis. B, The lateral part of the os frontis, which 
gives origin to part of the temporal muscle. C, The superci- 
liary ridge. D, The superciliary hole through which the 
frontal vessels and nerves pass. EE, The orbitar pjjl^esses. 
F, The middle of the transverse suture. G, The upper part of 
the orbit. H, The foramen opticum. I, The foramen lacerum. 
K, the inferior orbitar fissure. L, The os unguis. M, The ossa 
nasi. N, The os maxillare superius. O, Its nasal process. P, 
The external orbitar hole through which the superior maxil- 
lary vessels and nerves pass. Q, The os malee. R, A passage 
for small vessels into or out of, the orbit. S, The under part 
of the left nostril. T, The septum narium. U, The os spon- 
giosum superius. V, The os spongiosum inferius. W, The 
edge of the alveoli, or spongy sockets for the teeth. X, The 
maxilla inferior. Y, The passage for the inferior maxillary 
vessels and nerves. 

Fig. 3. A Side-view of the Skull. 
A, The OS frontis. B, The coronal suture. C, The os pa- 
rietale. D, An arched ridge which gives origin to the temporal 
muscle. E, the squamous suture. F, The squamous part of the 
temporal bone: and farther foi- wards, the temporal process of 
the sphenoid bone. G, The zygomatic process of the temporal 
bone. H, The zygomatic sntu't\ I, the mastoid process of the 
temporal bone. K, the meatus auditorius externus, L, Theor- 
biter plate of the frontal bone, under which is seen the trans 



:>m 



Explanation of the Plates of Osteology, 3 

verse suture. M, The pars plana of the ethmoid bone. N,The 
OS unguis. 0, The right os nasi. P, The superior maxillary 
bone. Q, Its nasal process. R, The two dentes incisores. S, 
The dens caninus. T, The two small molares. U, The three 
large molares. V, The os malse. W, The lower jaw. X, Its 
angle. Y, The coronoid process. Z, The condyloid process 
by which the jaw is articulated with the temporal bone. 
Fig. 4. The posterior and right side of the skull. 

A, The OS frontis. BB, The ossa parietalia. C, The sagit- 
tal suture. D, The parietal hole, through which a small vein 
runs to the superior longitudinal sinus. E, The lambdoid su- 
ture. FF, Ossa triquetra. G, The os occipitis. H, The squa- 
mous part of the temporal bone. I, the mastoid process. K, 
The zygoma. L, The os malse. M, The temporal part of the 
sphenoid bone. N, The superior maxillary bone and teeth. 
Fig. 5. The External Surface of the Os Frontis. 

A, The convex part. B,Part of the temporal fossa. C, The 
-external angular process. D, The internal angular process E, 
The nasal process. F, The superciliary arch. G, The super- 
ciliary hole. H, The orbitar plate. 

Fig. 6. The Internal Surface of the Os Frontis. 

AA, The serrated edge which assists to form the coronal 
suture. B, The external angular process. C, The Internal 
angular process. D, The nasal process. E, The orbitar plate. 

F, The cells which correspond with those of the ethmoid bone. 

G, The passag&from the frontal sinus. H, The opening which 
receives the cribriform plate of the ethmoid bone. I, The ca- 
vity which lodges the fore part of the brain. K, The spine to 
vvliich the f;ilx is fixed. L, The groove which lodges the su- 
perior longitudinal sinus. 

Plate XX. - 

Fig. 1. A Back View of the Skeleton. 
A A, The ossa parietalia. B, The sagittal suture. C, The 
lambdoid suture. I), The occipital bone. E, The squamous 
suture. F, The mastoid process of the temporal bone. G, The 
OS mahe. H, The palate plates of the superior maxillary bones. 
I, The maxilla inferior. K, 'I'he teeth of both jaws. L, The 
seven cervical vertebrae. M, Their spinous processes. N, 
Their transverse and oblique processes. O, The last of the 
twelve dorsal vertebree. P, The fifth or last lumbar vertebra. 
Q, The transverse processes. R, The oblique processes. S, The 
spinous process. T, The upper part of the os sacrum. U, The 
posterior holes which transmit small blood vessels and nerves. 



4 Explanation of the Plates of Osteology. 

V, The under part of the os sacrum which is covered by a 
membrane. W, The os coccygis. X, The os ilium. Y, Its 
spine or crest. Z, The ischiatic niche, a, The os ischium, by 
Its tuberosity, c, Its Spine, d, The os pubis, e. The foramen 
hydroideum. f. The seventh or last true rib. g, The twelfth or 
last false rib. h. The clavicle, i, The scapula, k, Its spine. 1, 
Its acromion, m, Its cervix, n, Its superior costa. o. Its pos- 
terior costa. p, Its inferior costa. q. The os humeri, r. The ra- 
dius, s, The ulna, t, Its olecranon, u, All the bones of the 
carpus, excepting the os pisiforme, which is seen in plate XIX. 
fig. 1. v, The five bones of the metacarpus, w. The two bones 
of the thumb, x. The three bones of each of the fingers. y.The 
two sesamoid bones at the root of the left thumb, z. The os 
femoris. 1, The trochanter major. 2, The trochanter minor, 
3, Thelineaaspera. 4, The internal condyle. 5, The external 
condyle. 6 6, The semilunar cartilages. 7, The tibia. 8, The 
malleolus internus. 9, The fibula. 10, The malleolus externus. 
11, The tarsus. 12, The metatarsus. 13, The toes. 

Fig. 2. The External Surface of the Left Os Parietale. 
A, The convex smooth surface. B, The parietal hole. C, An 
arch made by the beginning of the temporal muscle. 

Fig. 3. The Internal Surface of the same bone. 
A, Its superior edge, which, joined with the other, forms 
the sagittal suture. B, The anterior edge which assists in the 
formation of the coronal suture. C, The inferior edge for the 
squamous suture. D, The posterior edge for the lambdoid su- 
ture. E, A depression made by the lateral sinus. F, The 
prints of the arteries of the dura mater. 

Fig. 4. The external Surface of the Left Os Temporum. 

A, The squamous part. B, The mastoid process. C, The 
zygomatic process. D, The styloid process. E, The petrosal 
process. F, The meatus auditorius externus. G, The glenoid 
cavity for the articulation of the lower jaw. H, The foramen 
stylo-mastoideum for the portio dura of the seventh pair of 
nerves. I, Passages for blood-vessels into the bone. K, The 
foramen mastoideum through which a vein goes to the lateral 
sinus. 

Fig.. 5. The Internal Surface of the Left Os Temporum. 

A, The squamous part; the upper edge of which assists in 
forming the squamous suture. B, The mastoid process. C, The 
styloid process. D, The pars petrosa. E, The entry of the 
seventh pair, or auditory nerve. F, The fossa, which lodges a 
part of the lateral sinus. G, The foramen mastoideum. 



Explanation of the Plates of Osteology, 5 

Fig. 6. The External Surface of the Osskous Circle, which 
terminates the meatus auditorius externus. 
A, The anterior part. B, A small part of the groove in 
which the membrana tympani is fixed. 

N. B. This, with the subsequent bones of the ear, are here 
delineated as large as the life. 

Fig. 7. The Internal Surface of the Osseous Circle. 
A, The anterior part. B, The groove in which the mem- 
brana tympani is fixed. 

Fig. 8. The situation and Connexion of the Small Bones of 
the Ear. 
A, The malleus. B, The incus. C, The os orbiculare. D, 
The stapes. 
Fig. 9. The Malleus, with its Head, Handle, and Small 

Processes. 
Fig. 10. The Incus, with its Body, Superior and Inferior 
Branches. 
Fig. 11. The Os Orbiculare. 
Fig. 12. The Stapes, with its Head, Base, and two Crura. 
Fig. 13. An Internal View of the Labyrinth of the Ear. 
A, The hoi low part of the cochlea, which forms a share of the 
meatus auditorius internus. B, The vestibulum. CCC, The 
semicircular canals. 

Fig. 14. An External View of the Labyrinth. 
A, The semicircular canals. B, The fenestra ovalis which 
leads into the vestibulum. C, The fenestra rotunda which 
opens into the cochlea. D, The difterent turns of the cochlea. 
Fig. 15. The Internal Surface of the Os Sphenoides. 
AA. The temporal processes. BB, The pterygoid process- 
es. CC, The spinous processes. DD, The anterior clinoid 
processes. E, The posterior clinoid process. F, The anterior 
process which joins the ethmoid bone. G, The sella turcica 
for lodging the glandula pituitaria. H, The foramen opticum. 
K, The foramen lacerum, L, The foramen rotundum. M, The 
foramen ovale. N, The foramen spinale. 

Fig. 16. The External Surface of the Os Sphenoides. 
AA, The temporal processes. BB, The pterygoid process- 
es. CC, The spinous processes, D, The processes azygos. E, 
The small triangular processes which grow from the body of 
the bono. FF, The orifices of the splienoid sinuses. G, The 
foramen lacerum. II, The foramen rotundum. I, The foramen 
ovale. K, The foramen pterygoideum. 



# 



6 Explanation of the Plates of Osteology. 

Fig. 17 The External View of the Os Ethmoides. 
A, The nasal lamella. BB, The grooves between the nasal 
lamella and ossa spongiosa superiora. CC, The ossa spongiosa 
superiora. DD, The sphenoidal cornua. See Fig. 16. E. 
Fig. 18. -he Internal View of the Os Ethmoides. 
A, The crista galli. B, The cribriform plate, with the dif- 
ferent passages of the olfactory nerves. CC, Some of the eth- 
moidal cells. D, The right as planum. EE, The sphenoidal 
cornua. 

Fig. 19. The right Sphenoidal Cornu. 
Fig. 20. The left Sphenoidal Cornu. 
Fig. 21. The External Surface of the Os Occipitis. 
A, The upper part of the bone. B, The superior arched 
ridge. C, The inferior arched ridge. Under the arches are 
prints made bj the muscles of the neck. DD, The two con- 
dyloid processes which articulate the head with the spine. E, 
The cuneiform process. F, Ihe foramen magnum through 
which the spinal marrow passes. GG, The posterior condyloid 
foramina which transmit veins into the lateral sinuses. HH, 
The foramina lingualia for the passage of the nintli pair of 
nerves. 

Fig. 22. The internal Surface of the Os Occipitis. 
A A, the two sides which assist to form the lambdoid suture. 
B, The point of the cuneiform process, where it joins the 
sphenoid bone. CC, The prints made by the posterior lobes of 
the brain. DD, Prints made by the lobes of the cerebellum. 
E, The cruciform ridge for the attachment of the process of 
the dura mater. F, The course of the superior longitudinal 
sinuses. GG, The course of the two lateral sinuses. H, The 
foramen magnum. IJ, The posterior condyloid foramina. 

Plate XXI. 
Fig. 1. A ^ide-View of the Skeleton. 
AA, The ossa parietalia. B, The sagittal suture. C, The os 
occipitis. DD, The lambdoid suture. E, The squamous part 
of the temporal bone. F, The mastoid process. G, The meatus 
auditorius externus. H, The os frontis. I, The os malse. K, 
The OS maxillare superius. L, The maxilla inferior. M, The 
teeth of both jaws. N, The seventh, or last ceVvical vertebra. 
O, The spinous processes. P, Their transverse and oblique 
processes. Q, The twelfth or last dorsal vertebra. R, The 
fifth, or last, lumbar vertebra. S, The spinous processes. T, 
Openings between the vertebra; for the passage of the spinal 
nerves. U, The under end of the os sacrum. V, The os coc- 



Explanation of the Plates of Osteology. 1 

eygis. W, The OS ilium. X, The Tanterior spinous processes. 
Y, The posterior spinous processes. Z, Ischiatic niche, a, Tlue 
right OS ilium, b, The ossa pubis, c, The tuberosity of the 
left OS ischium, d, The Scapula, e, Its spine, f, The os hu- 
meri, g, The radius, h, The ulna, i, The carpus, k, The me- 
tacarpal bone of the thumb. 1, The metacarpal bones of the 
fingers, m, The two bones of the thumb, n, The three bones 
of each of the fingers, o, The os femoris. p, Its head, q, The 
trochanter major, r, The external condyle, s. The rotula. t, 
The tibia. u,The fibula, v. The malleolus externus. w. The 
astragalus, x, 'I he os calcis. y, I he os naviculare. z, Ihe 
three ossa cuneiforma. 1, 'Ihe os cuboides. 2, The five meta- 
tarsal bones. 3, 1 he two bones of the great toe. 4, The three 
bones of each of the small toes. 

Fig. 2. A View of the Internal Surface of the Base of the 

Skull. 
AAA, The two tables of the skull with the diploe. BB, 
The orbitar plates of the frontal bone. C, The crista galli, 
with cribriform plate of the ethmoidal bones on each side of 
it, through which the first pair of nerves pass. D, ihe cunei- 
form process of the occipital bone. E, '1 he cruciform ridge. 
F, The foramen magnum for the passage of the spinal mar- 
row. G, The xygoma, made by the joining of the zygomatic 
processes of the os temporum and os mal^e. H, '! he pars squa- 
mosa of the OS temporum. I, The pars mammillaris. K, f he 
pars petrosa. L, The temporal process of the sphenoid bone. 
MM, The anterior clinnid processes. N, The posterior cli- 
noid process, (3, The sella turcica, P, The foramen opticum. 
for the passage of the optic nerve and ocular artery of the 
left side. Q, Ihe foramen lacerum, for the third, fourth, sixth, 
and first of the fifth pair of nerves and ocular vein. R, 'she 
foramen rotundum, for the second of the fifth pair. S, The 
foramen ovale, for the third of the fifth pair. T, The foramen 
spinale, for the principal artery of the dura mater. U, -he 
entry of the auditory nerve. V, The passage for the laternal 
sinus. W, The passage of the eighth pair of nerves. X, The 
passage of the ninth pair. 

Fig, 3. A View of the External Surface of the Base of the 
Skull. 
A, The two dentes incisoresof the right side. B, The dens 
caninus. C, The two small molares. D, The three large mo- 
lares. E, The foramen incisivum, which gives passage to small 
blood vessels and nerves. F, 'I he palate-plates of the ossa 
maxillaria and palati, joined by the longitudinal and trans- 
verse palate sutures. G, Ihe foramen palatinum posterius, for 



8 Explanation of the Plates of Osteology. 

the palatine vessels and nerves. H, I'lie os maxillare superius 
of the right side. I, The os malse. K, The zygomatic process 
of the temporal bone. L, The posterior extremity of the ossa 
spongiosa. M, The posterior extremity of the vomer which 
forms the back part of the septum nasi. N, The pterygoid pro- 
cess of the right side of the sphenoid bone. 00, (he foramina 
ovalia. PP. The foramina spinalia. QQ, The passages of the 
internal carotid arteries. R, A hole between the point of each 
pars petrosa and cuneiform process of the occipital bone, whicli 
is filled up with a ligamentous substance in the recent subject. 
S, The passage of the left lateral sinus. T, The posterior con- 
dyloid foramen of the left side. U, The foramen mastoideum. 
V, i he foramen magnum. W, The inferior orbitar fissure. X, 
The glenoid cavity, for the articulation of the lower jaw. Y^ 
The squamous part of the temporal bone. Z, The mastoid 
process, at the inner side of which is a fossa for the posterior 
belly of the digastric muscle, a, The styloid process, b. The 
meatus auditorius externus. c. The left condyle of the occi- 
pital bone, d. The perpendicular occipital spine, ee, The in- 
ferior horizontal ridge of the occipital bone, if. The superior 
horizontal ridge, which is opposite to the crucial ridge where 
the longitudinal sinus divides to form the lateral sinuses, ggg, 
The lambdoid suture, h, The left squamous suture, i, The 
parietal bone. 

Fig. 4. The anterior surface of the Ossa Nasi. 

A, The upper part, which joins the os frontis. B, The un- 
der end, which joins the cartilage of the nose. C, The inner 
edge, where they join each other. 

Fig. 5. The posterior surface of the Ossa Nasi. 

AA, Their cavity, which forms part of the arch of the nose. 
BB, Their ridge or spine, which projects a little to be fixed 
to the fore part of the septum narium. 

Fig. 6. The external surface of the Os Maxillare Superius 
. of the left side. 

A, The nasal process. B, The orbitar plate. C, The un- 
equal surface which joins the os malse. D, The external or- 
bitar hole. E, The opening into the nostril. F, The palate- 
place. G, The maxillary tuberosity. H, part of the os palati. 
I, The two dentes incisores. K, The dens caninus. L, The 
two small dentes molares. M, The three large dentes molares. 
Fig. 7. The internal surface of the Os Maxillare Superius 
and Os Palati. 

A, The nasal process. BB, Eminences for the connexion 
of the OS spongiosum inferius. D, The under end of the la- 
chrymal groove. E, The antrum maxillare. F, The nasal spine. 



Explanation of the Plates of Osteology. 9 

between which and B is the cavitv of the nostril. G, The 
palate-plate. H. Theorbitar part of the os palati. I, The na- 
sal plate. K, The suture which unites the maxillary and palate 
bones. L, The pterygoid process of the palate bone. 

Fig. 8. The external surface of the right Os Unguis. 
A, Theorbitar part. B, The lachrymal part. C, The ridge 
between them. 

Fig. 9. The internal surface of the right Os Unguis. 
This side of the bone has a furrow opposite to the external 
ridge ; all behind this is irregular, where it covers part of the 
ethmoidal cells. 

Fig. 10. The external surface of the left Os Mal^e. 
A, The superior orbitar process. B, The inferior orbitar 
process. C, The malar process. D, The zygomatic process. 
E, The orbitar plate. F, A passage for small vessels into or 
out of the orbit. 

FjG. 11. The internal surface of the left Os Mal^. 
A, the superior orbitar process. B, The inferior orbitar 
process. C, The malar process. D, The zygomatic process. 
E, The internal orbitar plate or process. 

Fig. 12. The external surface of the right Os Spongiosum In- 

FRRIUS. 

A, The anterior part. B,The hock-like process for cover- 
ing part of the antrum maxillare. C, A small process which 
covers part of the under end of the lachrymal groove. D, The 
inferior edge turned a little outwards. 

Fig. 13. The internal surface of the Os Spongiosum Tnferius, 

A, The anterior extremity. B, The upper edge which joins 
the superior maxillary and palate bones. 
Fig. 14. The posterior and external surface of the right Os 
Palati. 

A, The orbitar process. B, The nasal lamella. C, The 
pterygoid process. D, The palate process. 
Fig. 15. The interior and external surface of the right Os 
Palati. 

A, The orbitar process. B, An opening through which the 
lateral nasal vessels and nerves pass. C, The nasal lamella. 
D, The pterygoid process. E, The posterior edge of the palate 
process for the connexion of the velum palati. F, The inner 
edge by which the two ossa palati are connected. 
Fig. 16. The right side of the Vomf.r. 

A, The Upper edge which joins the nasal lamella of the 

B 



iO Exflanation of the Plates of Osteology. 

ethmoid bone and the middle cartilage of the nose. B, The 
inferior edge, which is connected to the superior maxillary 
and palate bones. C, The superior and posterior part which 
receives the processes azygos of the sphenoid bone. 
Fig. 17. The Maxilla Inferior. 

A, The chin. B, The base and left side. C, The angle. D, 
The coronoid process. E, The condyloid process. F, The 
beginning of the inferior maxillary canal of the right side, for 
the entry of the nerves and blood vessels. G, The termination 
of the left canal. H, The two dentes incisores. I, The dens 
caninus. K, The two small molares. L, The three large mo- 
lares. 

Fig. 18. The dliFerent classes of the Teeth. 

1, 2, A fore and back view of the two anterior dentes in- 
cisores of the lower jaw. 3, 4, Similar teeth of the upper-jaw. 
5, 6, A fore and back view of the dentes canini. 7, 8, The an- 
terior dentes molares. 9, 10, 11, The posterior dentes molares. 
12, 13, 14, 15, 16, Unusual appearances in the shape and 
size of the teeth. 

Fig. 19. The external surface of the Os Hyoides. 

A, The body. BB, The cornua. CC, The appendices. 

Plate XXI. 

Fig. 1, A Posterior View of the Ster-num and Clavicles, 
with the ligament connecting the clavicles to each other, 
a. The posterior surface of the sternum, bb. The broken 
ends of the clavicle, cccc. The tubercles near the extremity 
of each clavicle, d. The ligament connecting the clavicles. 

Fig. 2. A Fore-view of the Left Scapula, and a half of the 
Clavicle, with their Ligaments. 
The spine of the scapula, b. The acromion, c, The infe- 
rior angle, d. Inferior costa. e, Cervix, f. Glenoid cavity co- 
vered with cartilage for the arm-bone, gg, The capsula liga- 
ment of the joint, h, Coracoid process, i, the broken end of 
the clavicle, k. Its extremity joined to the acromion. 1, A li- 
gament coming out single from the' acromion to the coracoid 
process, m, A ligament coming out single from the acromion, 
and dividing into two, which are fixed to the coracoid process. 

Fig. 3. The Joint of the elbow of the left arm, with the Li- 
gaments. 
a. The os humeri, b, Its internal condyle, cc, The two 
prominent parts of its trochlea appearing through the capsu- 
lar ligament, d, The ulna, e, The radius, f, The part of the 
ligament includinathe head of the radius. 



s_e>T) 




Explanation of the Plates of Osteology. 1 i 

Fig. 4. The Bones of the Right-Hand, with thePALji in view. 

a, The radius, b, The ulna, c, The scaphoid bone of the 
carpus, d, The os lunare. e, The os cuneiform, f, The os 
pisiforme. g, Trapezium, h, Trapezoides. i, Capitatum. k, 
Unciforme. 1, The four metacarpal bones of the fingers, m, 
The first phalanx, n, The second phalanx, o, The third pha- 
lanx, p, The metacarpal bone of the thumb, q, The first jointo 
r, The second joint. 
Fig. 5. The posterior View of the bones of the Left Hand. 

The explication of Fig. 4. serves for this figure ; the same 
letters pointing out the same bones, though in a difterent view. 

Fig. 6. The Upper Extremity of the Tibia, with the Semilu- 
nar Cartilages of the Joint of the Knee, and some Ligaments, 
a, The strong ligament which connects the rotula to the tu- 
bercle of the tibia. bb,The parts of the extremity of the tibia, 
covered M-ith cartilage, which appear within the semilunar 
cartilages, cc. The semilunar cartilages, d. The two parts of 
what is called the cross ligament. 
Fig. 7. The Posterior View of the Joint of the Right Knee. 

a. The os femoris cut. b, Its internal condyle, c. Its ex- 
ternal condyle. d,The back part of the tibia, e, The superior 
extremity of the fibula, f, The edge of the internal semilunar 
cartilage, g, An oblique ligament, h, A large perpendicular 
ligament, i, A ligament connecting the femur and fibula. 
Fig. 8. The Anterior View of the Joint of the Right Knee. 

b. The internal condyle, c, Its external condyle, d. The 
part of the os femoris, on which the patella moves, e, A per- 
pendicular ligament. fF, The two parts of the crucial liga- 
ments, gg, The edges of the two moveable semilunar carti- 
lages, h. The tibia, i. The strong ligament of the patella, k, 
The back part of it where the fat has been dissected away. 1, 
The external depression, m, The internal one. n, The cut 
tibia. 

Fig. 9. A View of the inferior part of the Bones of The Right 

Foot. 
a. The great knob of the os calcis. b, A prominence on its 
outside, c, The hollow for the tendons, nerves, and blood ves- 
sels, d, The anterior extremity of the os calcis. e, Part of the 
astragalus f, Its head covered with cartilage, g, The internal 
prominence of the os naviculare. h, The os cuboides. i, The 
OS cuneiform internum ; k. — Medium : 1, — Externum, m. 
The metatarsal bones of the four lesser toes, n, The first — o, 
The second — p, The third phalanx of the four lesser toes, q. 



12 Explanation of the Plates of Osteology. 

The metatarsal bones of the great toe. r. Its first — s, Its se- 

•cood Joint. 

Fig. 10. The Inferior Surface of the two large Sesamoid Bones, 

at the first Joint of the Great Toe. 
Fig. 11. The Superior View of the Bones of the Right Foot. 

a, b, as in Fig. 9. c, The superior head of the astragalus, d, 
■&c. a's in Fig. 9. 
Fig. 12. The View ofthe Sole of the Foot, with its ligaments. 

a, The great knob of the os calcis. b, The hollow for the 
tendons, nerves, and blood vessels, c, The sheaths of the 
flexores pollicis and digitorum longi opened, d, The strong 
cartilaginous ligament supporting the head of the astragalus, 
e, h, Two ligaments which unite into one, and are fixed to the 
nietatarsal bone ofthe great toe. f, A ligament from the knob 
of the OS calcis to the metatarsal bone of the little toe. g, A 
strong triangular ligament, which supports the bones of the 
tarsus, i. The ligaments of the joints of the five nietatarsal 
bones. 

Fig. 13. a, The head of the thigh bone of a child, b. The 
ligamentum rotundum connecting it to the acetabulum, c. 
The capsular ligament ofthe joint with its arteries injected. 
d. The numerous vessels of the mucilaginous gland injected. 

Fig. 14. The Back-view of the Cartilages of the Larynx, 
with the Os Hjoides. 

a, The posterior part of the base of the os hyoides. bb, Its 
cornua. c, The appendix of the right side, d, A ligament sent 
out from the appendix of the left side, to the styloid process 
of the temporal bone, e, The union of the base with the left 
cornu. ft', The posterior sides of (g) the thyroid cartilage, hh. 
Its superior cornua. ii. Its inferior cornua. k, The cricoid 
cartilage. 11, The arytenoid cartilages, m, The entry into the 
lungs, named glottis, n. The epiglottis, oo. The superior car- 
tilages of the trachea, p. Its ligamentous back part. 
Fig. 15. The superior Concave surface ofthe Sesamoid Bones 

at the first joint of the Great Toe, with their Ligaments. 

a, Three sesamoid bones, b^ The ligamentous substance in 
which they are formed^ 




n-^'KlS:^^ 



Explanation of the Plates of the Muscles. 13 

EXPLANATION OF PLATES XXIII and XXIV. 
PLATE XXIII. 

Fig. 1. The Muscles immediately under tTie common te- 
guments on the anterior part of the body are represented on 
the right sidej and on the left side the Muscles are seen which 
come in view when the exterior ones are taken away. 

A, The frontal muscle. B, The tendinous aponeurosis 
which joins it to the occipital ; hence both named occipiio -fron- 
talis. C, Attolens aureni. D, The ear. E, Anterior auris. FF, 
Orbicularis palpebrarum. G, Levator labii superioris alfetjue 
nasi. H, Levator anguli oris. I, Zygomaticus minor. K, Zy- 
gomaticus major. L. Masseter. M, Orbicularis oris. N, De- 
pressor labii inferioris. 0, Depressor anguli oris. P, Buccina- 
tor. QQ, Platysma myoides. RR, Sterno-cleido-mastoida^us. 
3, Part of the trapezius. T, Part of the scalejii. 

Superior Extremity.— U.Deltoides. V,Pectoralis major. 
W, Part of the latissimus dorsi. XX. Biceps iiexor cubiti. 
YY, Part of the brachials externus. ZZ, The beginning of 
the tendinous aponeurosis (from the biceps,) which is spread 
over the muscles of the fore-arm. aa, Its strong tendon insert- 
ed into the tubercle of the radius, bb, Part of the brachialis 
internus. c. Pronator radii teres, d, Flexor carpi radialis. e, 
Partof the flexor carpi ulnaris. f, Palmaris longus. g, Aponeu- 
rosis palmaris. 3, Palmaris brevis. 1, Ligamentum carpi an- 
nulare. 2 2, Abductor minimi digiti. h, Supinator radii lon- 
gus. i, The tendons of the thumb, k, Abductor pollicis. 1, 
Flexor pollicis longus. mm, The tendons of the flexor subli- 
mis perforatus, profundus perforans, and lumbricales. — The 
sheaths are entire in the right hand, — in the left cut open to 
show the tendons of the flexor profundus perforating the 
sublimis. 

Muscles not referred to — ^in the left superior extremity. — 
n, Pectoralis minor, seu serratus anticus minor, o, The two 
heads of (xx) the biceps, p, Coraco-brachialis. qq, The long 
head of the triceps extensor cubiti. rr, Teres major, ss, Sub- 
acapularis. tt, Extensores radiales. u, Spinator brevis. v, The 
cut extremity of the pronator terres. w, Flexor siihlimis per- 
foratus. X, Part of the flexor profundus, y, Flexor pollicis 
longus. z, Part of the flexor pollicis brevis. 4, Abductor mi- 
nimi digiti. 5, The foijr lumbricales. 

Trunk. — 6, Serrated extremities of the serratus anticus 
inajor. 7 7, Obliquus externus abdominis. 8 8, The linea al 



14 Explanation of the Plates of the Muscles. 

ba. 9, The umbilicus. 10. Pyramidalis. 11 11, The sper- 
matic cord. On the left side it is covered by the cremaster. 
12 12, Rectus abdominis. 13, Obliquus internus. 14 14, &c. 
Intercostal muscles. 

Inferior Extremities.— a a, The gracialis. 6 &, Parts of 
the triceps, cc, Pectialis. dd. Psoas magnus. ee, Iliacus 
internus. /, Part of the glutseus medius. g. Part of the glu- 
teus minimus, h, Cut extremity of the rectus cruris, i i. 
Vastus externus. h. Tendon of the rectus cruris. Zf, Vastus 
internus. * Sartorius muscle. ** Fleshy origin of the tensor 
vaginse f?emoris or membranosus. Its tendinous aponeurosis 
covers (i) the vastus externus on the right side, mm. Patella. 
nn, Ligament or tendon from it to the tibia, o, Rectus cru- 
ris, p, Crurgeus. q q, The tibia, r r, Part of the Gemellus, 
or gastrocnemius externus. sss, Part of the soleus or gastroc- 
nemius internus. t. Tibialis anticus. u. Tibialis posticus, vv, 
Peronsei muscles, ivw. Extensor longus digitorum pedis, xx. 
Extensor longus pollicis pedis, y, Abductor poUicis pedis. 
Fig. 2. The Muscles, Glands, &c. of the Left Side of the face 

and neck, after the common Teguments and Platysraa 

myoides have been taken off. 

a, The frontal muscle, b, Temporalis and temporal artery, 
c, Orbicularis palpebrarum, d, Levator labii superioris alse- 
qui nasi, e. Levator anguli oris, f, Zygomaticus. g, De- 
pressor labii inferioris. h, Depressor anguli oris, i, Bucci- 
nator, k, Masseter. 11, Parotid gland, m, Its duct, n, 
Sterno-cleido-mastoidseus. o. Part of the trapezius, p, 
Sterno-hyoidseus. q, Sterno-thyroideeus. r, Omo-hyoidseus, 
f, Levator scapulse. tt, Scaleni. u. Part of the splenius. 
Fig. 3. The Muscles of the Face and Neck in view after the 
exterior ones are taken away. 

aa, Corrugator supercilii. b. Temporalis, c. Tendon of the 
levator palpebrse superioris. d, Tendon of the orbicularis 
palpebrarum, e, Masseter. f, Buccinator, g. Levator an- 
o-uli oris, h, Depressor labii superioris alseque nasi, i, Or- 
bicularis oris, k, Depressor anguli oris. 1, Muscles of the 
OS hyoides. m, Sterno-cleido-mastoideeus. 
Fig. 4. Some of the Muscles of the Os Hyoides and Submax- 
illary Gland. 

a, Part of the masseter muscle, b, Posterior head of the 
digastric, c. Its anterior head, dd, Sterno-hyoideeus. e, 
Omo-hyoidgeus. f, Stylo -hyoidseus. g. Submaxillary gland 
in situ. 



Explanation of the Plates of the Muscles. 15 

Fig. 5, The Submaxillary Gland and Duct. 
a, Musculus mylo-hyoidffius. b, Hyo-glossus. c, Submaxil- 
lary gland extra situ, d. Its duct. 

Plate XXIV. 

Fig. 1, The Muscles immediately under the common te- 
guments on the posterior part of the body, are represented on 
the right side • and on the left side the Muscles are seen 
which come in view when the exterior ones are taken away. 

Head. — AA, Occipito-frontalis. B, Attollens aurem. C, 
Part of the orbicularis palpebrarum. D, Masseter. E, Ptery- 
goidseus internus. 

Trunk. — Right side. FFF, Trapezius seu cucularis.GGGG, 
Latissimus doi-si. H, Part of the obliquuis externus abdominis. 

Trunk. — Left side. I, Splenius. K, Part of the complexus. 
L, Levator scapulse. M, Rhomboides. NN, Serratus posticus 
inferior. O, Part of the longissimus dorsi. P, Partof the sacro- 
lumbalis. Q, Part of the semi-spinalis dorsi. R, Part of the 
serratus anticus major. S, Part of the obliquus internus ab- 
dominis. 

Superior Extremity. — Right side. T, Deltoides. U, Tri- 
ceps extensor cubiti. V, Supinator longus. WW, Extensores 
carpiradialis longior and brevior. XX. Extensor carpi ulnaris. 
Y Y, Extensor digitorum communis. Z, Abductor indicis. 1 2 3, 
Extensores poUicis. 

Superior Extremity. — Left side, a, Supra Spinatus. b, In- 
fraspinatus, c, Teres minor, d, Teres major, e, Triceps exten- 
sor cubiti. f f, Extensores carpi radiales. g, Supinator brevis. 
h, Indicater. 1 2 3, Extensores pollicis. i, Abductor minimi 
digiti. k, Interossei. 

Inferior Exfremity. — Right side. 1, Glutseus maxiraus. 
m. Part of the Glutseus medius. n, Tensor vaginae femoris. o, 
Gracilis, pp, Abductor femoris magnus. q, Part of the vastus 
internus. r. Semimembranosus, s, Semitendinosus. t, Long 
head of the biceps flexor cruris, uu. Gastrocnemius externus 
seu gemellus, v, Tendo Achillis. w, Soleus seu gastrocne- 
mius internus. xx, Peroneeus lons,us and brevis. y, Tendons 
of the flexor longus digitorum pedis; — and underthem *flexor 
brevis digitorum pedis, z, Abductor minimi digiti pedis. 

Inferior Extremity. — Left side, m, n, o.pp, q, r, s. t, v, w 
w, X x^y, z, Point the same parts as in the right side, a, Pyri- 
formis.i' 6. Gemini, cc. Obturator internus. a, Quadratus fe- 
moris. e, Coccygaeus. /, The short head of the biceps flexor 
cruris, gg, Plantaris. h, Poplitsfcus. i. Flexor longus pollicis 
pedis. 



16 Explanation of the Plates of the Muscles. 

Fig. 2. The Palm of the Left Hand after the common Tegu- 
ments are removed, to show the Muscles of the Fingers, 
a, Tendon of thefiexor carpi radialis. b, Tendon of the flex- 
or carpi ulnaris. c, Tendons of the flexor sublimis perforatus, 
profundus perforans and lumbricales. d, Abductor pollicis. 
ee, Flexor pollicis longus. f, Flexor pollicis brevis. g, Palrna- 
ris brevis. h, Abductor minimi digiti. i, Ligamentum carpi- 
annuiare. k, A probe put under the tendons of the flexor di- 
gitorum sublimis; which are performed by 1, the flexor digito- 
rum profundus, mmmm, Lumbricales. n, Abductor pollicis. 

Fig. 3. A fore-view of the foot and Tendons of the Flexores 
Digitorum. 

a, Cut extremity of the tendo Achillis. b, Upper part of the 
astragalus, c, Os calcis. d, Tendon of the tibialis anticus. e, 
Tendon of the extensor pollicis longus. f, Tendon of the 
peronseus brevis. g, Tendons of the flexor digitorum longus, 
with the nonus Vesalii. hh, The whole of the flexor digitorum 
brevis. 

Fig. 4. Muscles of the Anus. 

aa, An outline of the buttocks, and upper part of the 
thighs, b, The testes contained in the scrotum, cc. Sphincter 
ani. d, Anus, e, Levator ani. ff", Erector penis, gg, Accele- 
rator urinee. h, Corpus cavernosum urethree. 
Fig. 5. Muscles of the Penis. 

aa, b, d, ee, fF, h, point the same as in fig. 4. c, Sphincter 
ani. gg, Transversalis penis. 



EXPLANATION of PLATES XXV, XXVI and XXVIL 

Plate XXV. 

Fig. 1. Shows the Contents of the Thorax and Abdomen In 

situ. 
1, Top of the trachea, or wind -pipe. 2 2, The internal ju- 
gular veins. 3 3, The subclavian veins. 4, The vena cava de- 
scendens. 5, The right auricle of the heart. 6, The right ven- 
tricle. 7, Part of the left ventricle. 8, The aorta descendens. 
9, The pulmonary artery. 10, The right lung, part of which 
is cut off to show the great blood vessels. 11, The left lung 
entire. 12 12, The anterior edge of the diaphragm. 13 13, 
The two great lobes of the liver. 14, 1 he ligamentum rotun- 
dum. 15, The gall-bladder. 16, The stomach. 17 17, The 
jejunum and ilium. 18, The spleen. 



Explanatio7i of the Plates of Osteology. 17 

Fig. 2, Shows the organs subservient to the Chylopoietic Vis- 
cera,— with those of Urine and Generation. 

11, The under side of the two great lobes of the liver, a, 
Lobulus spigelii. 2, The ligamentum rotundum. 3, The gall- 
bladder. 4, The pancreas. 5, The spleen. 6 6, The kidneys. 
7, The aorta descendens. 8, Vena cava ascendens. 9 9, The 
renal veins covering the arteries. 10, A probe under the sper- 
matic vessels and a bit of the inferior mesentric artery, and 
over the ureters. 11 11, The ureters. 12 12, The iliac ar- 
teries and veins. 13, The rectum intestinum. 14, The bladder 
of urine. 

Fig. S. Shows the Chylopoietic Viscera, and Organs subser- 
vient to them, taken out of the body entire. 

AA, the under side of the two great lobes of the liver. B, 
Ligamentum rotundum. C, The gall-bladder. D, Ductus 
cysticus. E, Ductus hepaticus. F, Ductus communis chole- 
dochus. G, Vena portartim. H, Arteria hepatica. H, The sto- 
mach. KK, Venee and arterise gastro-epiploicge, dextree and 
sinistrse. LL, Venseand arteriee coronarise ventriculi. M,The 
spleen. NN, Mesocolon, with its vessels. 000, Intestinum 
colon. P, One of the ligaments of the colon, which is a bun- 
dle of longitudinal muscular fibres. QQQQ, Jejunum and ilium 
RR, Sigmoid flexure of the colon with the ligament continuedy 
and over. S, The rectum intestinum. TT, Levatores ani. U, 
Sphincter ani. V, The place to which the prostate gland is 
connected. W, The anus. 
Fig. 4. Shows the Heart of a Fcetus at the full time, with 

the Right Auricle cut open to show the Foramen Ovale, 

or passage between both Auricles. 

a, '! he right ventricle, b. The left ventricle. cC, Ihe outer 
side of the right auricle stretched out. dd, > he posterior side, 
which forms the anterior side of the septum, e, f he foramen 
ovale, with the membrane or valve which covers the left side. 
f, Vena cava inferior passing through, g^ A portion of the di- 
aphragm. 

Fig. 5. Shows the Heart and Large Vessels of a Foetus at the 
full time. 

a, The left ventricle, b. The right ventricle, c, A part of 
the right auricle, d. Left auricle, ee, The right branch of the 
pulmonary Artery, f, Arteria pulmonalis. gg. The left branch 
of the pulmonary artery, with a numberof its largest branch- 
es dissected from the lungs, h, ' he canalis arteriosus, i, The 
arch of the aorta, k k, he aorta descendens, 1, The left sub- 
clavian artery, m, The left carotid artery, n. The right carotid 

C 



18 Explanation of the F kites of the Muscles, 

artery, o, The right subclavian artery, p, The origin of the 
right carotid and right subclavian arteries in one common 
trunk, q, The vena cava superior or descendens. r, The right 
common subclavian'vein. s, The left common subclavian vein. 
N. B. All the p^rts described in this figure are to be found 
in the adult, except the canalis arteriosus. 

Plate XXVL 

Fig. 1. Exhibits the more superficial Lymphatic Vessels of 

the Lower Extremity. 
A, The spine of the os ilium, B, Theos pubis. C, The iliac 
artery. D, The knee. E, E, F, Branches of the crural artery. 
G, The mosculus gastrocnemius. H, The tibia. I, The tendon 
of the musculus tibialis anticus. On the outlines, a, A lym- 
phatic vessel belonging to the top of the foot, b, Its first di- 
vision into branches, c, c, c. Other divisions of the same lym- 
phatic vessel, d, A small lymphatic gland, e, The lymphatic 
vessels which lie between the skin and the muscles of the 
thigh, ff, Two lymphatic glands at the upper part of the 
thigh below the groin, gg, Other glands, h, A lymphatic ves- 
sel which passes by the side of those glands without com- 
municating with them ; and bending towards the inside of the 
groin at (i,) opens into the lymphatic gland (k.) 11, Lympha- 
tic glands in the groin, which are common to the lymphatic 
vessels of the genitals and those of the lower extremity, m, 
n, A plexus of lymphatic vessels passing on the inside of the 
iliac artery. 

Fig. 2. Exhibits a Back View of the Lower Extremity, dis- 
sected so as to show the deeper-seated Lymphatic Vessels 
which accompany the Arteries. 

A, The OS pubis. B, The tuberosity of the ischium. C, That 
part of the os ilium which was articulated with the os sacrum. 

D, The extremity of the iliac artery appearing above the groin. 

E, The knee. FF, The two cut surfaces of the triceps muscle, 
which was divided to show the lymphatic vessels that pass 
through its perforation along with the crural artery. G, The 
edge of the musculus gracilis. H, The gastrocnemius and so- 
leus much shrunk by being dried, and by the soleus being se- 
parated from the tibia to expose the vessels. I, The heel. K, 
The sole of the foot. L, The superficial lymphatic vessels 
passing over the knee, to get to the thigh. On the out-lines; 
M, The posterior tibial artery, a, A lymphatic vessel accom- 
panying the posterior tibial artery, b, The same vessel cross- 
ing the artery, c, A small lymphatic gland, through which this 



Explanation of the Plates of the Muscles. 19 

deep-seated lymphatic vessel passes, d, The lymphatic ves- 
sel passing under a small part of the soleiis, which is left at- 
tached to the bone, the rest being removed, e, The lymphatic 
vessel crossing the popliteal artery, f, g, h, Lymphatic glands 
in the ham, through which the lymphatic vessel passes, i. The 
lymphatic vessel passing with the crural artery, through the 
perforation of the triceps muscle, k, The lymphatic vessel, 
after it has passed the perforation of the triceps, dividing into 
branches which embrace the artery (1.) m, A lymphatic gland 
belonging to the deep seated lymphatic vessel. At this place 
those vessels pass to the fore part of the groin where they 
communicate with the superficial lymphatic vessel, n, A part 
of the superficial lymphatic vessel appearing on the brim of 
the pelvis. 
Fig. 3. Exhibits the Trunk of the Human Subject prepared to 

show the Lymphatic Vessels and the Ductus Thoracicus. 

A, The neck. BB, The two jugular veins. C, The vena ca- 
va superior. DDDD, The subclavian veins. E, The beginning 
of the aorta, pulled to the left side by means of a ligature, in 
order to show the thoracic duct behind it. F, The branches 
arising from the curvature of the aorta. GG, The two carotid 
arteries. HH, The first ribs. II, The trachea. KK, The spine. 
LL, The vena azygos. MM, The descending aorta. N, The 
cceliac artery, dividing into three branches, O, The superior 
mesenteric artery. P, The right crus diaphragmatis. QQ, The 
two kidneys. R, The right emulgent artery. SS, The exter- 
nal iliac arteries, g, d, The musculi psose. T, The internal 
iliac artery. U, The cavity of the pelvis. XX, The spine of 
the OS ilium. YY, The groins. «, A lymphatic gland in the 
groin, into which lymphatic vessels from the lower extremity 
are seen to enter, bh, The lymphatic vessels of the lower ex- 
tremities passing under Poupart's ligament, cc, A plexus of 
the lymphatic vessels lying on each side of the pelvis, d. The 
psoas muscle with lymphatic vessels lying upon its inside. <?, 
A plexus of lymphatics, which having passed over the brim of 
the pelvis at (c,) having entered the cavity of the pelvis, and 
received the lymphatic vessels belonging to the viscera con- 
tained in that cavity, next ascends and passes behind tlie iliac 
artery to (,^.)/, Some lymphatic vessels of the left side pass- 
ing over the upper part of the os sacrum ; to meet those of the 
right side, g, The right psoas, with a large plexus of lympha- 
tics lying on its inside, hh. The plexus lying on each side of 
the spine, iii, Spaces occupied by the lymphatic glands, ky 
The trunk of tlie lacteals lying on the under side of the supe 



20 Explanation of the Plates of the Muscles, 

rior mesenteric artery. I, The same dividing into two branch- 
es, one of which passes on each side of the aorta ; that of the 
right side being seen to enter the thoracic duct at (m.) m. The 
thoracic duct beginning from the large lymphatics, w, The 
duct passing under the lower part of the crus diaphragmatis, 
and under the right emulgent artery, o. The thoracic duct pe- 
netrating the thorax, p. Some lymphatic vessels joining that 
duct in the thorax, q. The thoracic duct passing under the 
curvature of the aorta to get to the left subclavian vein. The 
aorta being drawn aside to show the duct, r, A plexus of lym- 
phatic vessels passing upon the trachea from tlie thyroid gland 
to the thoracic duct, 

PLATE XXVII. 

Fig. 1. Represents the Under and Posterior Side of the Blad- 
der of Urine, &c. 

a, The bladder, bb. The insertion of the ureters, cc. The 
vasa deferentia, which convey the semen from the testicles to 
dd. The vericula seminales,— and pass through e. The pros- 
tate gland, to discharge themselves into f, The beginning of 
the urethra. 

Fig. 2. A transverse Section of the Penis. 

gg, Corpora cavernosa penis, h, Corpus cavernosum ureth- 
rse. i, Urethra, k. Septum penis. 11, The Septum between 
the corpus cavernosum urethrge and that of the penis. 
Fig. 3. A Longitudinal Section of the Penis. 

mm, The corpora cavernosa penis, divided by o. The sep- 
tum penis, n, The corpus cavernosum glandis, which is the 
continuation of that of the urethra. 

Fig. 4. Represents the Female Organs of Generation. 

a, That side of the uterus which is next the os sacrum. 1, 
Its fundus. 2, Its cervix, bb, The fallopian or uterine tubes, 
•which open into the cavity of the uterus; — but the other end 
is open within the pplvis, and surrounded by c c, The fimbriae, 
d. d, The ovaria. e, The os internum uteri, or mouth of the 
womb, f f. The ligamenta rotunda, which passes without the 
belly, and is fixed to the labia pudendi. gg, The cut edges of 
the ligamenta lata, which connects the uterus to the pelvis. 
h. The inside of the vagina, i. The orifice of the urethra, k, 
The clitoris surrounded by (I,) The praeputium. mm, The la- 
"bia pudendi. nn. The nymphae. 

Fig. 5. Shows the Spermatic Ducts of the Testicle filled with 
Mercury. 

4., The vas deferens. B, Its beginning, which forms the 



Explanation of the Plates of the Muscles, 21 

posterior part of the epididymis. C, The middle of the epi- 
didymis, composed of serpentine ducts. D, The head or an- 
terior part of the epididymis unravelled, e e e e, The whole 
ducts which compose the head of the epididymis unravelled, 
ff. The vasadeferentia. gg, Rete testis, hh, Some rectilineal 
ducts which send off the vasa deferentia. i i. The substance 
of the testicle. 

Fig. 6. The right Testicle entire, and the Epididymis filled 
with Mercury. 
A, The beginning of the vas deferens. B, The vas deferens 
ascending towards the abdomen. C, The posterior part of the 
epididymis, named globus minor. D, The spermatic vessels 
inclosed in cellular substance. E, The body of the epididy- 
mis. F, Its head, named globus major. G, Its beginning from 
the testicle. H, The body of the testicle, inclosed in the tu- 
nica albuginea. 



EXPLANATION of PLATE XXVIII. 

This plate represents the Heart in situ, all the large Arte- 
ries and Veins, with some of the Muscles, &c. 

Muscles, &c. — Superior Extremity. — a, Masseter. b, 
Complexus. C, Digastricus. d, Os hyoides. e. Thyroid gland. 
f, Levator scapulae, g, Cucullaris. h h, The clavicles cut. i, 
The deltoid muscle, k. Biceps flexor cubiti cut. 1, Coraco- 
brachialis. m, ^'riceps extensor cubiti. n, The heads of the 
pronator teres, flexor carpi radiales, and flexor digitorum sub- 
limis, cut. o. The flexor carpi-ulnaris, cut at its extremity, p. 
Flexor digitorum profundus, q. Supinator radii longus, cut at 
its extremity, r, Ligamentum carpi transversale, s, Exten- 
sores carpi radiales. t, Latissimus dorsi. u, Anterior edge of 
the serratus anticus major, vv, The inferior part of the dia- 
phragm, w w. Its anterior edge cut. xx, The kidneys, y, 
Transversus abdominis, z, Os ilium. 

Inferior Extremity,-^— a, Psoas magnus. b, Iliacus internus. 
c, The fleshy origin of the tensor vagina femoris. dd, The os- 
sa pubis cut from each other, e, Musculus pectineus cut from 
its origin./. Short head of the triceps abductor femoris cut. g. 
The greathead of the triceps. A, The longhead cut. i. Vastus 
internus. A;, Vastus externus. /, Crureus. m. Gemellus, n, 
Soleus. 0, Tibia, p, Peronseus longus. </, Peronaeus brevis. r, 
Fibula. * 

Heart and Blood-vessels. — A, The heart, with the co- 
ronary artery and veins. B, 1 he right auricle of the heart. C. 
The aorta ascendens. D, The left subclavian artery. E, he 
left carotid artery. F, The common trunk which sends oft" the 



22 Explanation of the Plates of the Muscles, 

right subclavian and right carotid arteries. G, The carotis ex- 
terna. H, Arteria facialis, which sends off the coronary arte- 
ries of the lips. I, Arteria temporalis profunda. K, Aorta de- 
scendens. LL, he iliac arteries, — which sends off MM, The 
femoral or crural arteries. N. B. The other arteries in this 
figure have the same distribution as the veins of the same; 
name: — And generally, in the anatomical plates, the descrip- 
tion to be found on the one side, points out the same parts in 
the other. 1, The frontal vein. 2, The facial vein. 3, Vena 
temporalis profunda. 4, Vena occipitalis. 5, Vena jugularis 
externa. 6, Vena jugularis interna, covering the arteria caro- 
tis communis. 7, The vascular arch on the palm of the hand, 
which is formed by, 8, The radial artery and rein, and, 9, 
The ulnar artery and vein. 10 10, Cephalic vein. 1 1, Basilic 
vein, that on the right side cut. 12, Median vein. 13, The 
humeral vein, which, with the median, covers the humeral 
artery. 14 14, The external thoracic or mammary arteries and 
veins. 15, The axillary vein, covering the artery. 16 16, Ihe 
subclavian veins, which, with (6 6) the jugulars, form, 17, 
The vena cava superior. 18, The cutaneous arch of veins on 
the fore part of the foot. 19, The vena tibialis antica, cover- 
ing the artery. 20, The vena profunda femoris, covering the 
artery. 21, The upper part of the vena saphena major. 22, 
The femoral vein. 23 23, The iliac veins. 24 24, Vena cava 
inferior. 25 25, The renal veins covering the arteries. 26 26, 
The diaphragmatic veins. 



EXPLANATION of PLATE XXIX. 

Fig. 1 Represents the Inferior part of the Brain ;— 'the An- 
terior part of the whole Spine, including the Medulla Spina-: 
lis ; — -with the origin and large portions of all the Nerves. 

AA, The anterior lobes of the cerebrum. BB, The lateral 
lobes of the cerebrum. CC, The two lobes of the cerebellum. 
D, Tuber annulare. E, The passage from the third ventricle 
to the infundibulum. F, The medulla oblongata, which sends 
off the medulla spinalis through the spine. GG, That part of 
the OS occipitis which is placed above (HH) the transverse 
processes of the first cervical vertebra. II, &c. The seven 
cervical vertebrge, with their intermediate cartilages. KK, &c. 
The twelve dorsal vertebrse, with their immediate cartilages^ 
LL, &c. The five lumbar vertebrae, with their intermediate 
cartilages. M, The os sacrum, N, The os coccygis. 



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Explanation of the Plates of the Muscles. S8 

Nerves. — 1 1, The first pair of nerves, named olfactory, 
which go to the nose. 2 2, The second pair, named optic^ which 
o-oes to form the tunica retina of the eye. 3 3, The third pair, 
named motor occult ; it supplies most of the muscles of the 
eye-ball. 4 4, The fourth pair, named pathetic^ — which is 
wholly spent upon the musculus trochlearis of the eye. 5 5, 
The fifth pair divides into three branches. — The first, named 
opthahnic^ goes to the orbit, supplies the lachrymal gland, and 
sends branches out to the fore-head and nose. — i he second, 
named superior maxillary, supplies the teeth of the upper 
jaw, and some of the muscles of the lips. — Ihe third, named 
inferior maxillary, is spent upon the muscles and teeth of the 
lower jaw, tongue, and muscles of the lips. 6 6, The sixth 
pair, which, after sending off the beginning of the intercostal 
or great sympathetic, is spent upon the abductor oculi. 7 7, 
The seventh pair, named auditory, divides mto two branches. — 
The largest, named portio mollis, is spent upon the internal 
ear. ihe smallest, ;joWzo dura, joins to the fifth pair within 
the internal ear by a reflected branch from the second of the 
fifth ; and within the tympanum, by a branch from the third 
of the fifth, named chorda tympani. — Vid. fig. 3. near B 8 8, 
&c. The eighth i^mr,x\ame^ par vagum, — which accompanies 
the intercostal, and is spent upon the tongue, larynx, pharynx, 
lungs, and abdominal viscera. 9 9, The ninth pair, which are 
spent upon the tongue. 10 10, &c. The intercostal, or great 
sympathetic, which is seen from the sixth pair to the bottom 
of the pelvis on each side of the spine, and joining with all 
the nerves of the spine ;— In its progress supplying the heart, 
and, with the par vagum, the contents of the abdomen and 
pelvis. 1111, The accesorius, which is spent upon the ster- 
nocleido-mastoideeus and trapezius muscles. 12 12, The first 
cervical nerves; — 15 13, The second cervical nerves; — both 
spent upon the muscles that lie on the neck, and teguments 
of the neck and head. 14 14, The third cervical nerves, which, 
after sending off (15 15, &c.) the phrenic nerves to the di- 
aphragm, supply the muscles and teguments that lie on the 
side of the neck and top of the shoulder. 16 16, I he brachial 
plexus, formed by the fourth, fifth, sixth, seventh cervicals, 
and first dorsal nerves: which supply the muscles and tegu- 
ments of the superior extremity. 17 17, 'Ihe twelve dorsal, 
or proper intercostal nerves, which are spent upon the inter- 
costal muscles and some of the large muscles which lie upon 
the thorax. 18 18, The five lumbar pairs of nerves, which 
supply the lumbar and abdominal muscles, and some of he 
teguments and muscles of tlie inferior extremity. 19 19. The 



24 Expla7mtion of the Plates of the Muscles. 

sacro-sciatic, or posterior craral nerve, formed by the two in- 
ferior lumbar, and three superior of the os sacrum. This larg**; 
nerve supplies the greatest part of the muscles and teguments 
of the inferior extremity. 20, The stomachic plexus, formed 
by the eighth pair. 21 21, Branches of the solar or cceliac 
plexus, formed bythe eighth pair and intercostals, which sup- 
ply the stomach and chylopoietic viscera. 22 22, Branches of 
the superior and inferior mesenteric plexuses, formed by the 
eighth pair and intercostals, which supply the chylopoietic vis- 
cera, with part of the organs of urine and generation. 23 23, 
Nerves which accompany the spermatic cord. 24 24, The hy- 
pogastric plexus, v/hich supplies the organs of urine and ge- 
neration within the pelvis. 

Fig. 2, 3, 4, 5, Show diiFerent Views of the Inferior part of the 
Brain, cut perpendicularly through the Middle, — with the 
Origin and large Portions of all the Nerves which pass out 
through the Bones of the Cranium,— -and the three first 
Gervicals. 

A, The anterior lobe. B, The lateral lobe of the cerebrumo 
C, One of the lobes of the cerebellum. D, Tuber annulare. 
E, Corpus pyramidale, in the middle of the medulla oblong- 
ata. F, The corpus olivare, in the side of the medulla ob- 
longata. G, The medulla oblongata. H, The medulla spinalisl 
Nerves.— 1 2 3 4 5 6 7 8 and 9, Pairs of Nerves. 10 10, 
Nervus accessorius, which comes from— 11, 12, and 13, The 
three first cervical nerves. 



EXPLANATION of PLATE XXX. 

Figure 1, Shows the Lachrymal Canals, after theCommofi 
Teguments and Bones have been cut away. 

a, The lachrvmal gland, b, The two puncta lachrymaliaj 
from which the two lachrymal canals proceed to c, The la- 
chrymal sac. d, The large lachrymal duct, e, Its opening into 
the nose, f, The carunca lachrjmalis. g. The eye^ball. 

Fig. 2. An interior View of the Coats and Humours of the 

Eye. 
a a a a. The tunica sclerotica cut in four angles, and turned 
back, b b b b, The tunica choroides adhering to the inside of 
the sclerotica, and the ciliary vessels are seen passing over— 
G c, The retina which covers the vitreous humour, d d, The 
ciliary processes, which were continued from the choroid coat^ 
e e, The iris, f. The pupil. 



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Explanation of the Plates of the Muscles, S5 

Fig. S. Shows the Optic Nerves, and Muscles of the Eye. 

a, a, The two optic nerves before they meet, b, The two 
optic nerves conjoined, c, The right optic nerve, d, Muscu- 
lus attolens palpebrae superioris. e, Attollens oculi. f, Abduc- 
tor, gg, Obliquus superior, or trochlearis. h, Abductor, i. The 
eye -ball. 

Fig. 4. Shows the Eye-ball with its Muscles. 

a, The optic nerve, b, Musculus trochlearis. c, Part of the 
08 frontis, to which the trochlea or pulley is fixed through 
which, — d, The tendons of the trochlearis pass, e, Attollens 
oculi. f. Adductor oculi. g, Abductor oculi. h, Obliquus in- 
ferior, i, Part of the superior maxillary bone to which it is fix- 
ed, k. The eye-ball. 
Fig. 5. Represents the Nerves and Muscles of the Right 

Eye, after part of the Bones of the orbit have been cut 

away. 

A, The eye-ball. B, The lachrymal gland. C, Musculus 
abductor oculi. D, Attollens. E, Levator palpebrae superior- 
is. F, Depressor oculi. G, Abductor. H, Obliquus superior, 
with its pulley. I, its insertion into the sclerotic coat. K, Part 
of the obliquus iaferior. L, The anterior part of the os fron- 
tis cut. M, The crista galli of the ethmoid bone- N, The 
posterior part of the sphenoid bone. 0, Transverse spinous 
process of the sphenoid bone. P, The carotid artery, denuded 
where it passes through the bones. Q, The carotid artery 
within the cranium. R, The ocular artery. 

Nerves. — a a, The optic nerve. — b. The third pair, c, Its 
joining with a branch of the first branch of the fifth pair, to 
form 1, — The lenticular ganglion, which sends off the ciliary 
nerves, d. e e, The fourth pair, f, The trunk of the fifth pair, 
g, The first branch of the fifth pair, named ophthalmic, h. 
The frontal branch of it. i. Its ciliary branches, along with 
which the nasal twig is sent to the nose, k. Its branch to the 
lachrymal gland. 1, The lenticular ganglion, m. The second 
branch of the fifth pair, named superior maxillary, n, The 
third branch of the fifth pair, named inferior maxillary, o. The 
sixth pair of nerves— which sends off p. The beginning of 
the great sympathetic, q, The remainder of the sixth pair, 
spent on c. The abductor oculi. 

Fig. 6, Represents the head of a youth, where the upper 
part of the cranium is sawed off, — to show the upper part of 
the brain, covered by the pia mater, the vessels of which are 
minutely filled with wax. 

AA. The cut edges of the upper part of the cranium. B, 



26 Explanation of the Plates of the Musceh. 

The two tables and intermediate diploe. BB, The two hemi- 
spheres of the cerebrum. CC, The incisure made by the falx. 
D, Part of the tentorium cerebello super expansum. E, Part 
of the falx, which is fixed to the crista galli. 
Fig. 7. Represents the parts of the External Ear, with the 
Parotid Gland and its Duct. 

a a. The helix, b, The antihelix. c. The antitragus. d. The 
tragus, e, The lobe the ear. f, Thecavitasinnominata. g, The 
scapha. h. The concha, ii, The parotid gland, k, A lym- 
phatic gland, which is often found before the tragus. 1, The 
duct of the parotid gland, m, Its opening into the mouth. 
Fig. 8. A view of the posterior part of the external ear, 

meatus auditorius, tympanum with its small bones and Eus- 
tachian tube, of the right side. 

a, The back part of the meatus, with the small ceruminous 
glands, b, The incus, c, Malleus, d. The chorda tympani. e, 
Membrana tympani. f. The Eustachian tube, g, Its mouth 
from the fauces. 
Fig. 9. Represents the anterior part of the right external 

ear, the cavity of the tympanum — its small bones, cochlea 

and semicircular canals. 

a, The malleus, b, Incus, with its long leg, resting upon 
the stapes, c, Membrana tympani. d, e, The Eustachian tube 
covered by part of — f f, The Musculus circumflexus palati. 1, 
2, 3, The three semicircular canals. 4, The vestibule. 5, The 
cochlea. 6, The portio mollis of the seventh pair of nerves. 
Fig. 10. Shows the muscles which compose the fleshy substance 
of the Tongue. 

a a. The tip of the tongue, with some of the papillae mini- 
ma:, b, The root of the tongue, c, Part of the membrane of 
the tongue, which covered the epiglottis, d d. Part of the 
musculus hyo-glossus. e,Thelingualis. f, Genio-glossus. g g, 
Part of the stylo-glossus. 



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